Booklets and Articles Index  
                         THE HEBREW CALENDAR:
                      A Mathematical Introduction

                      Prepared by: JOHN A. KOSSEY
                        Editor: HERMAN L. HOEH

                             FIRST EDITION
                       AMBASSADOR COLLEGE PRESS
                         Pasadena, California
                          1971, 1974 Edition

                        ----------###----------

                               PROGRAM I

              USING THE TIME UNITS OF THE HEBREW CALENDAR
 

INTRODUCTION

Why should YOU study the Hebrew calendar?

     One of the major identifying signs of the Church of God is the
observance of the Sacred Festivals. As you study the twenty-third
chapter of Leviticus, you will notice that God employed a calendar to
indicate when each holy day must be properly kept during the year. The
Jews were given the responsibility of preserving that calendar for the
rest of the world.

     Since it is the responsibility of the Church to announce the time
of each festival to the congregations, detailed understanding of the
Hebrew calendar is not even necessary for a lay church member. When a
holy day is to be kept is not for the individual Christian to decide.

     On the other hand, the education you are privileged to receive as
an Ambassador College student equips you with a special depth of
biblical understanding. Shallow or sketchy knowledge of basic
background areas would lessen one's effectiveness. But working out the
calendar principles yourself is going to widen your perspective.

     You already know that the holy days portray God's master plan of
salvation for mankind. Shouldn't you also have a working knowledge of
the very calendar which houses God's Sacred Festivals?

     This is why a study of the Hebrew calendar is included in
Theological Research I-II.
 

THE PURPOSE OF THESE LEARNING PROGRAMS

     Your study of the Hebrew calendar in this course has two major
facets. One is the historical development of the calendar. This is the
primary function of the class lectures. The other is for you to achieve
needed computational facility with the calendar itself.

     Fortunately, the Hebrew calendar requires surprisingly little
mathematical sophistication. A fifth grade background in arithmetic
will suffice! Nevertheless, a certain number of skills and concepts
must be learned for you to become adept at working with the Hebrew
calendar. These programs are designed to provide you with that
understanding and practice.

     Just what will you be able to accomplish when you complete this
series of learning programs?

     For any year, such as 4 BC, 31 AD, 1520 AD, and 1979 AD, you will
correctly determine the dates on a common Roman calendar of the holy
days listed in Leviticus 23.

     How long will this operation require? With nothing but a pencil
and a blank sheet of paper, you might need anywhere from thirty to
forty-five minutes. If you use a table of reduced numbers (which is
included in one of the programs), it might take you only ten to fifteen
minutes.

     That skill is the OVERALL GOAL of this series of programs. Another
less tangible aim is to give you the confidence that you can actually
SUCCEED in working a calendar problem!

     To that end, each learning program takes a necessary part of the
main goal, and gives you the practice needed to become adept at it.
Success will breed success as you progress!

     The first page of each learning program has a clear statement of
what you must be doing by the time you complete the program. You might
think of each program as a "checkpoint" on route to your destination.
Be sure you can accomplish each program goal before going on to the
next one.

     One word of caution. Have you ever learned mathematics simply by
glancing over the textbook or watching someone else work through a
problem? No, you can't! The exercises in each program are entirely for
your benefit. In most cases, these exercises will be worked out in
detail later in the program. This is for you to have a model with which
to compare your own procedures and to check your work immediately for
errors.

     But WORK you must! Proverbs 4:13 says to "take fast hold of
instruction; let her not go." Learning the mathematical operations of
the Hebrew calendar will take ACTIVE EFFORT. With this diligence, you
will achieve the exhilaration only success can bring.

                        ----------###----------

                               Contents
                                                        Program

Introduction                                                i
Using the time units of the Hebrew calendar                 1
Calculating the day of the week of the molad Tishri         2
Calculating the day of the month of the molad Tishri        3
Using tables to find the molad Tishri                       4
Making Roman leap year and Julian/Gregorian corrections     5
Applying the postponement rules to find Tishri one          6
Counting the days of the week and the days of the month     7
Determining the dates of the annual festivals               8

                        ----------###----------

PERFORMANCE GOAL 1A:

     Without hesitation or uncertainty you will write (or recite) from
memory in any order the following time relationships:

     1 part (chalyek)      =   76 moments (regaim)
     1 hour                = 1080 parts (chalakim)
     1 day                 =   24 hours
     1 week                =    7 days
     1 lunar month         =   29 days 12 hours 793 parts
     1 common year         =   12 lunar months
     1 intercalary year    =   13 lunar months
     1 nineteen year cycle =  235 lunar months, or 12 common
                                 years & 7 intercalary years
 

PERFORMANCE GOAL 1B:

     With only paper and pencil (or pen), you will accurately add,
subtract, multiply, and divide the time relationships listed in lA as
necessary to compute specified problems. Large numbers will be "reduced
to lowest terms" when requested. For example,

     28 hours reduces to 1 day, 4 hours
     31 hours 650 parts reduces to 1 day, 7 hours, 650 parts.
 

PERFORMANCE GOAL 1A

     In order for you to become adept with calendar calculations, you
must become very familiar with a minimal number of time relationships.
Some of these you already know; others require memorization. These
numbers will occur so frequently that you simply must know them.
Otherwise, the lessons will take much longer to understand and you will
feel frustrated in the process. Learn them now -- for your own benefit.

     For a detailed yet concise description of the time elements of the
Hebrew calendar, consult either of the following references:

          "The Jewish Encyclopedia", volume 3, "Calendar" (either new
or old edition).

          Burnaby, Sherrard Beaumont, "Elements of the Jewish and
Muhammadan Calendars". London: George Bell & Sons, 1901. 554 pages.
(See chapter II, page 21.)
 

     Here is a brief explanation of some of these time elements to
assist your memorization.

     DAY: Genesis 1:5 shows that the day begins in the evening. "And
the evening and the morning were the first day. " Although each day
begins at sunset, 6 PM is the arbitrary commencement of a new day for
CALENDAR CALCULATIONS.

     Christ put his divine approval upon dividing the day into
twenty-four hours. See John 11:9, which states, "Are there not twelve
hours in the day?" Context shows that this verse refers to the daylight
portion of a twenty-four hour period. For any given day the periods of
darkness and light are usually unequal. The total length of a day,
however, is always 24 hours--except for Divine intervention!

     HOUR: Instead of being divided into minutes and seconds, the hour
is divided into parts, or chalakim. One hour consists of 1080 parts, or
3600 seconds. Using parts instead of minutes and seconds has the
advantage of eliminating fractions. (The smaller unit, the moment or
rega, is seldom needed for fundamental calculations.) Both the hour and
the part are considered fixed units anywhere on earth, just as the
minute and the second are non-varying time elements.

     MONTH: A lunar month is the time needed for the moon to revolve
around the earth. Even though this period varies from month to month,
29 days 12 hours 793 parts is the traditional average used for
calculation. Actual calendars cannot be based upon 29 1/2 days, so the
Hebrew calendar incorporates months of 29 and 30 days.

     YEAR: The Hebrew calendar has two basic types of years, common and
intercalary. (The latter term is also called "embolismic.") An
intercalary Hebrew year will have 30 additional days, so it can also be
called a leap year. By contrast, recall that the Roman leap year has
366 days instead of 365. You should also remember that the following
terms are interchangeable for the Hebrew calendar:

     LEAP (year or month) = embolismic (year or month) =
INTERCALARY(year or month)

     Common years will have 353, 354, or 355 days. Leap years may have
383, 384, or 385 days.

     19 YEAR CYCLE: The Western world is accustomed to a solar year of
365 1/4 days, since the Roman calendar in common use is solar. This
means that a given month of the year will always occur during the same
season. January, for example, is invariably a winter month.

     On the other hand, the Hebrew year by itself does not closely
match the length of a solar year. Twelve months which are each
approximately 29 1/2 days results in a year which has only 354 days --
about eleven days less than a solar year of 365 1/4 days. A common
Hebrew year is thus SHORTER than a Roman year.

     What about a Hebrew leap year? Thirteen months of 29 1/2 days is
383 1/2 days, which is LONGER than a solar year.

     God has ordained that the holy days must be kept "in their
seasons" (Lev. 23:4). He also appointed BOTH the sun and the moon "for
signs, and for seasons, and for days, and years" (Genesis 1:14). This
means that the calendar which God designed to house His sacred
festivals would be luni-solar. The months must occur at the proper
times for the holy days to fall within the proper season of the year.

     How, then, are the Hebrew lunar months related to the solar year?
Every 19 solar years (of 365 1/4 days), the moon revolves around the
earth 235 times, each "lunation" being on the average 29 days, 12
hours, 793 parts. This remarkable astronomical relationship makes it
possible to combine common years and leap years together within a
fundamental pattern that repeats itself every nineteen years:

     12 common years (12 months each)is 144 months   (each month is
      7 leap years (13 months each)  is  91 months     29d, 12 h,
     -----------------------------------------------   793p)
     19 Hebrew years is 235 months  = 19 solar years

     You should be aware, however, that 235 lunar months is about an
hour and a half less than 19 Julian years. (To be precise, 235
lunations is 1 hour, 485 parts LESS than 19 Julian years.)

     The 19-year cycle is also known as the cycle of Meton, or the
Metonic cycle.

     Be sure you have MEMORIZED the time relationships listed at the
beginning of this section! Don't assume that you know them "pretty
well."
 

PERFORMANCE GOAL 1B

     The source of many errors in calendar calculations is faulty
arithmetic. Most occur in the basic addition, subtraction, and
multiplication operations. All of these skills you learned before high
school. Consequently, some review and practice are absolutely
necessary. WORK the problems; don't be deluded into thinking that
glancing over them will suffice.

ADDITION: The key to successful computation rests in one simple rule:

                         add only likes together

Just as 3 apples and 4 oranges don't equal 7 apples, neither does
adding 11 hours to 4 days equal 15 hours. Never put a number down
without being positively certain that you know what it represents. The
best way is to label every number: 671 p is 671 parts. Another way is
to keep like quantities in clearly defined columns:

                     days      hours      parts
                    ------    -------   -------
                       1         12        103
                       3         15       1186

This is the same as:   1 d       12 h      103 p
                       3 d       15 h     1186 p

Select a format you like and use it consistently. Here are some sample
problems:
 

          5 d       15 h        175 p
        + 1 d        7 h        801 p
        ------------------------------
          6 d       22 h        976 p        So long as you add only
                                             like quantities, no
                                             outstanding difficulties
                                             will happen.

          6 d       237 h      1189 p
        +24 d       107 h      2159 p
        ------------------------------
         30 d       344 h      3348 p        The numbers can become
                                             very large, as you can
                                             see. Later on you will
                                             learn how to reduce these
                                             to lowest terms.

          8 d        13 h       198 p
         18 d        23 h       432 p
         13 d        45 h      1835 p
      +   7 d        96 h       103 p
       -------------------------------
         46 d       177 h      2568 p        Adding a whole string of
                                             numbers together will
                                             often occur. Don't be
                                             afraid to double and
                                             triple-check your
                                             arithmetic!

Solve the following problems below. If you aren't "comfortable" by the
time you complete them, try to make up a few of your own for additional
practice.

1.1)          6 d          17 h            879 p
     +        3 d          14 h            198 p
     --------------------------------------------

1.2)         67 d          95 h            777 p
     +      275 d         777 h           2589 p
     --------------------------------------------
 

1.3)         55 d         178 h           976 p
             31 d           1 h           134 p
            178 d          23 h          1937 p
            225 d           9 h         11581 p
            308 d         768 h           649 p
     +       29 d          12 h           793 p
     ----------------------------------------------------------------
 

1.4)        131 d          29 h           433 p
            227 d           8 h           191 p
              0 d           1 h           485 p
     +      130 d          12 h           883 p
     ----------------------------------------------------------------
 

The answers to these problems appears below:
1.1)        9 d           31 h          1077 p
1.2)      342 d          872 h          3366 p
1.3)      826 d          991 h         16070 p
1.4)      488 d           50 h          1992 p

REDUCTION: Before attempting to subtract or multiply these numbers, it
will be helpful for you to understand how they are reduced.

You have learned how to reduce quantities such as inches to feet and
yards, or seconds to hours and minutes, back in junior high
mathematics:

     45 inches reduces to     1   yard    0 feet   9 inches
     49 inches reduces to     1   yard    1 foot   1  inch
    436 seconds    "       "  0   hours   7 min.  16  seconds
   3600 seconds    "       "  1   hour    0 min.   0  seconds

Reduction of large numbers is not difficult. An EQUIVALENT way of
saying exactly the same thing is all that you are doing. Both
quantities are equal.

The primary units in your calculations will be days, hours, and parts.
Each of these quantities are related to each other, as you have already
learned from performance goal 1A.
 

1. 5) Complete the following:

     ________ parts = 1 hour

     ________ hours = 1 day

The answers, of course, are 1080 parts in an hour, and 24 hours in a
day. This means that 1080 parts can be written as:

          0   days       1   hour       0   parts

In like manner, 24 hours can be shifted to the days column:

          1   day        0   hours      0   parts.

Take a quantity like 3 d, 49 h, 1400 p. How do you reduce it? What you
want to do is transfer all EXCESS WHOLE HOURS contained in the parts
column to the hours column. Then you will take out all the WHOLE days
contained in the hours column and move them to the days column. Just
like reading Hebrew, you work from right to left!

To reduce numbers, apply the following operations:

     1)   Divide the parts in the parts column by 1080. The whole
number in the quotient represents hours.

     2)   Add the whole number in the quotient to the hours column.
This becomes the "revised" hours. Place the remainder in the "reduced"
parts column. If remainder is 0, put this number in that column.

     3)   Take the revised number of hours and divide this by 24. The
whole number in the quotient is the number of whole days.

     4)   Add the whole number of days to the days column, and place
the remainder in the "reduced" hours column.

-----------------------------------------------------------------------
Reduced numbers for days, hours, parts will have:
          any number of days 23 or less hours 1079 or less parts
-----------------------------------------------------------------------
     Here's how to apply these rules to reduce 3 d, 49 h, 1400 p:

1)             1 h                         1 h  320 p
           ---------
     1080 / 1400 p
            1080
           ---------
             320
 

2)            1 h  320 p
     +  3 d  49 h
     --------------------
        3 d  50 h  320 p
 

3)         2                               2 d  2 h
         --------
     24 / 50 h
          48
         --------
           2
 

4)       2 d  2 h  320 p
     +   3 d
     --------------------
         5 d  2 h  320 p                   REDUCED

Problems with large numbers are handled the same way. The answer to 1.
2 is  342 d  872 h  3366 p.
 

1)             3 h                         3 h  126 p
           ------------
     1080 / 3366 p
            3240
           ---------
             126
 

2)               3 h  126 p
     +  342 d  872 h
     -----------------------
        342 d  875 h  126 p
 

3)           36 d                          36 d  11 h
          ---------
      24 /  875 h
             72
          ---------
            155
            144
          ---------
             11
 

4)      36 d  11 h  126 p
     + 342 d
     ----------------------
       378 d  11 h  126 p
 

Reducing numbers isn't difficult. Your accuracy will be enhanced if you
consistently stick to a single format. Slopping numbers down
haphazardly on the page is inviting computational errors.

1.6) Reduce 5, 796 parts.
1.7) Reduce 579, 600 parts.
1.8) Reduce 85 d  91 h  150,000 p.
1.9) Reduce 567 d  5228 h  254,404 p.

The answers to 1.6 - 1.9 are on the next pages. Work these problems on
separate paper, then compare your calculations with the complete
arithmetical details supplied.
 

1.6            5 h                          0 d  5 h  396 p answer
           ---------
     1080 / 5796 p
            5400
           ---------
             396
 

1.7            536 h                    536 h  720 p;  536 hours
          ---------------                              must be reduced.
     1080 / 579600 p
            5400
           ---------
             3960
             3240
            --------
              7200
              6480                22 d     22 d  8 h  720 p answer
             -------          --------
               720        24 / 536 h
                               48
                              -------
                                56
                                48
                               ------
                                 8
 

1.8       85 d 91 h 150,000 p

     (1)        138 h                      138 h  960 p;  add this to
           ------------                                   85 d 91 h.
     1080 / 150,000 p
            108 0
           -----------
             42 00
             32 40
             ---------
              9600
              8640
             ---------
               960
 

     (2)        138 h  960 p
          85 d   91 h
          -------------------
          85 d  229 h  960 p
 

     (3)         9 d                       9 d  13 h;  add together the
              --------                                 reduced 960 p,
          24 / 229 h                                   9 d  13 h, and
               216                                     85 d.
              --------
                13 h
 

     (4)        13 h  960 p
          85 d
          ------------------
          94 d  13 h  960 p             answer
 

1.9       567 d  5228 h  254,404 p
 

     (1)            235 h                  235 h  604 p
                -----------
          1080 / 254404 p
                 2160
                ---------
                  3840
                  3240
                ---------
                   6004
                   5400
                ---------
                    604 p
 

     (2)          235 h  604 p
          567 d  5228 h
          ---------------------
          567 d  5463 h  604 p
 

     (3)        227 d                      227 d  15 h
              --------
          24 / 5463 h
               48
              --------
                66
                48
              --------
                183
                168
              --------
                 15 h
 

     (4)  227 d  15 h  604 p
          567 d
          --------------------
          794 d  15 h  604 p
 

MULTIPLICATION: After adding days, hours, and parts, you will find that
multiplication is quite easy. The important key to correct
multiplication is that ALL TERMS must be multiplied! Forgetting to
multiply days while you complete the operation for the hours and parts
can easily happen if you aren't wary.

Look at a sample problem:

     2 d  16 h  595 p
                x 3
     -----------------
     6 d  48 h 1785 p    Notice that the multiplier operates
                         on the days, the hours, and the parts.

Multiplication can help you solve many problems that would take much
longer by straight addition. Here is an example:

How many days, hours, parts are in an AVERAGE common year?

You should easily remember:

          The number of lunar months in a common year;
          The number of days hours and parts in a lunar month.

If you cannot recall these numbers, return immediately to the first
page of this section and drill intensely on the time relations listed
in 1A.

A common year has 12 months. Each month has 29 d, 12 h, 793 p.
Therefore an average common year has:

       29 d   12 h   793 p
            x 12 months
      --------------------
       58     24    1586
       29     12     793
      -----  -----  ------
      348 d  144 h  9516 p

If this number were to be used in a series of computations, it could
stand "as is." On the other hand, when it is the final answer, can't
you see the need to reduce such a number? You may want to verify that
an average common year has 354 d  8 h  876 p. (This is worth
remembering.)

1.10  How many days, hours, and parts are in an average intercalary
year?

1.11  What number of d, h, p are in the 19 year cycle?
 

1.12  7 x (5 d 21 h 589 p) =  _____________

1.13  (4 d  8 h  876 p)  x 12 =  _____________

1.14  (18 d 15 h  589 p)  x  6 =  _____________
 

Problems 1.10 - 1.14 are worked out for you below.
 

1.10   29 d   12 h     793 p
          x 13 months
       ----------------------
       87     36     2,379
       29     12       793
       ----------------------
      377 d  156 h  10,309 p    This reduces to 383 d  21 h  589 p.
 

1.11 You may calculate this problem by two methods:
     a) add the lengths of 12 common years and 7 leap years together,
using the example and 3.10.
     b) Find the length of 235 lunations.

     Here's how method b) is solved:

         29 d    12 h    793 p
                       x 235 months
       ---------------------
        145      60     3965
        87      36     2379
       58      24     1586
      -----    -----  ------
       6815 d  2820 h 186355 p             This reduces to
                                             6939 d  16 h  595 p.
 

1.12    5 d   21 h   589 p
                    x  7
     ----------------------
       35 d  147 h  4123 p                 This reduces to
                                              41 d  6 h  883 p.
 

1.13    4 d    8 h   876 p
                    x 12
     ----------------------
        8     16    1752
       4      8     876
     ----------------------
       48 d   96 h 10512 p                 This reduces to
                                             52 d  9 h  792 p.

1.14   18 d  15 h   589 p
                   x  6
     ----------------------------------
      108 d  90 h  3534 p                  This reduces to
                                             111 d  21 h  294 p.
 

SUBTRACTION: This is the most error-prone operation for many students.
Two facets of subtraction are particularly troublesome:

     a) borrowing
     b) negative numbers

First look at a straight-forward subtraction problem:

         5 d   21 h  589 p
     -  (4 d   19 h   98 p)
     -----------------------
         1 d    2 h  491 p

Notice that the minus sign affects all the quantities in the second
line. Obviously, adding one of the units and subtracting the others
isn't kosher! The first principle to keep in mind:

     SUBTRACT ALL TERMS called for.

Practice on two of these problems, comparing your answer with that
given.
 

1.15     6 d  6 h  883 p
     -  (1 d  5 h  785 p
     ---------------------
                                           answer: 5 d  1 h  98 p
 

1.16 -  (  74 d  14 h   45 p)
          111 d  21 h  294 p
     -------------------------             answer: 37 d  7 h  249 p
                                           (You CAN subtract "upside
                                             down.")
 

In the next example, "borrowing" will be necessary:

          8 d  23 h  403 p
     -   (6 d  22 h  528 p)
     -----------------------
 

Since 1080 parts are in an hour, 8 d  23 h  403 p can be changed to
8 d  (23-1) h  (403 + 1080) p, or 8 d  22 h  1483 p. Be sure you
understand that neither expression is different. Borrowing merely
places the number in a more convenient form for subtraction.

By borrowing quantities as needed, the problem becomes ordinary
subtraction:

          8 d  22 h  1483 p
     -   (6 d  22 h   528 p)
     ------------------------
          2 d   0 h   955 p

In order to firm up the concept of borrowing in your mind, examine
another illustration:

         3 d   3 h     0 p
     -  (1 d  18 h  6000 p)
     -----------------------
 

On this problem, you cannot simply take one hour and transfer 1080
parts. A quick estimate will tell you that at least 6 hours need to be
changed to parts. Only 3 are in the hours column. Where do you get
them?

First, make up for the lack of hours in the second column by converting
a day (or more!) into hours.  3 d  3 h  0 p transfers to

     2 d  (24 + 3) h  0 parts, or  2 d  27 h  0 p.

Next borrow 6 hours and change them to parts:

     2 d  (27-6) h  (6480 + 0) p or,
     2 d      21 h        6480 p

Finally, subtract as required by the original problem:

         2 d  21 h  6480 p
     -  (1 d  18 h  6000 p)
     -----------------------
         1 d   3 h   480 p

Once in a while, you will find that in borrowing parts, you loose too
many hours for subtracting the hours. (Instead of 18 hours, suppose you
needed to subtract at least 22 hours in the above example.) When that
happens, simply borrow again from the next column to the left.

Borrowing is a reverse of reduction. Remember that both quantities are
equivalent -- before reduction and after reduction, or before and after
borrowing. A "golden rule" for these operations:

     ----------------------------------------------------------------
        WHAT YOU ADD TO ONE COLUMN MUST BE SUBTRACTED FROM ANOTHER.
     ----------------------------------------------------------------

1.17    40 d  6 h   104 p
     - (35 d  2 h  1141 p)
     ----------------------
                                           answer:  5 d  3 h  43 p
 

1.18     136 d  123 h  5291 p
     - (  89 d   29 h  7679 p)
     --------------------------
                                           answer:  47 d  91 h  852 p
 

1.19     21 d  30 h   811 p
     -  (17 d  69 h  2050 p)
     ------------------------
                                           answer:  2 d  7 h  921 p
 

The last complication to hurdle with subtraction is negative numbers.
By borrowing, you were able to keep numbers positive. But sometimes the
arithmetic is simplified by allowing numbers to become negative-without
borrowing.

There is nothing mysterious about negative time. All that it means is
time BEFORE a prescribed reference point. Such a reference point is the
blast-off of a moon launch. Events before lift-off are considered
negative times, as you heard on many telecasts: "t MINUS eight minutes
and holding." After the rocket lifts off, time becomes positive -- with
reference to the ZERO lift-off.

An expression like days, hours, parts refers to a particular instant in
time. When you are computing a problem, some of these numbers will
occasionally become negative. Nonetheless, the expression is still
identifying a precise moment. For example look at:

     5 d  -2 h  -810 p

Does this specified time occur on the fifth day or on the fourth? The
answer is the fourth day. This is immediately clear if you change the
expression to all positive signs by "borrowing. " These are the steps:

           5  d        -2  h          -810  p
        (5-1) d  (-2 + 24) h          -810  p
           4  d        22  h          -810  p
           4  d   (22 - 1) h  (-810 + 1080) p
           4  d        21  h           270  p

So  5 days  -2 hours  -810 parts is the same as  4 days  21 hours  207
parts.

You should become familiar enough with these negative expressions that
you accurately complete computations involving them. In ordinary
subtraction, all numbers were positive. Now you will find that
subtraction and addition of numbers of either sign frequently occurring
when you eventually calculate the days, hours, parts, of the month for
a conjunction of the moon.

The next example illustrates how this type of problem is worked:

            36 d   22 h   1284 p
           -17 d +  3 h -  541 p
          ------------------------
            19 d   25 h    743 p    or    20 d  1 h  743 p

When a number is not preceded by a sign, it is taken to be positive. A
few rules apply for these problems:

     adding two negatives together  (e.g. -5 + -3)  results in a
negative number larger than either (-8).

     adding a negative number and a positive number together is the
same as subtracting. The sign of   the  larger value (called the
absolute value in mathematics) is the sign of the final number.

          (-30  +  50  =  +20)
          (-48  +  38  =  -10)

     When you subtract a negative number from another negative number,
you change the sign of the number you are subtracting, and then add as
above. (-5  -  -3  =  -5  +  +3  =  -2)

Adding two negative numbers together results in a larger negative
number. Subtracting two negative numbers results in a smaller negative
number -- closer to zero. Any time you are working with negative
numbers, be sure that you carry the signs with you. Although you need
not specifically mark positive numbers, this may be advisable for you
initially in order to keep the signs clear in your mind. Whenever you
are subtracting, remember that the subtraction sign affects every
number (term) in the expression:

          45 d  23 h   150 p
      - ( -8 d  15 h  -125 p)
      ------------------------

Notice how the numbers subtracted change signs:

          45 d   23 h     150 p
          +8 d  -15 h  +  125 p
          ----------------------
          53 d    8 h     275 p

Try the following problem:

1.20     - 18 d  - 2 h  -  780 p
         -  0 d  - 1 h  -  485 p
         - 97 d  - 2 h  -  756 p
         + 74 d + 14 h  +  196 p           The answer appears below.
         + 13 d
         + 36 d + 22 h  + 1284 p
          -----------------------
 

1.20   The problem becomes easier if you total the negative quantities
separate from the positive, and then combine.

          - 18 d  -  2 h  - 780 p              74 d    14 h   196 p
             0 d  -  1 h  - 485 p              13 d
          - 97 d  - 22 h  - 756 p              36 d    22 h 1284 p
          ------------------------      -------------------------------
          -115 d  - 25 h - 2021 p            123 d     36 h 1480 p

           123 d    36 h   1480 p
          -115 d  - 25 h - 2021 p
          ------------------------
             8 d    11 h -  541 p          This reduces (by taking one
                                             hour and changing it to
                                             parts: + 1080 - 541) to
                                             8 d  10 h  539 p.

1.21 Work the next problem without reducing until the final step:

           210 d  - 15 h  -  971 p
        - ( 37 d    19 h  - 1185 p )
          --------------------------
                                           Change signs and subtract.
                                             Your result should be
                                             173 d  -34 h  +214 p.
                                             This reduces to
                                             171 d  14 h  214 p.
 

1.22  Add 92 d  581 h  471 p  to eight times (-10 d  -21 h  -204 p).
Then subtract  -152 d  - 589 h  188 p  from the sum. Reduce at the
final answer. How many days over a full number of weeks is this?

     First multiply: - 10 d  -  21 h  -  204 p
                                       x 8
                    --------------------------
                     - 80 d  - 168 h  - 1632 p
     Add:              92 d    581 h     471 p
                    ---------------------------
                     + 12 d  + 413 h  - 1161 p
 

     Subtracting  -152 d  -589 h  188 p, you change the signs and add:

                       12 d  +  413 h  - 1161 p
                    + 152 d  +  589 h  -  188 p
                    ----------------------------
                      164 d  + 1002 h  - 1349 p

     Borrow 2 hours, and then divide 1000 hours by 24 to convert the
hours column to a number less than 24. This gives:

                    205 d  16 h  811 p

To find how many days this is over a full number of weeks, you divide
by 7 the REDUCED number of days. 205 / 7 leaves a remainder of 2. Two
days plus 16 hours and 811 p is the time over a full number of weeks.

                              *   *   *

     After working the problems in this section, you should feel
confident about your ability to successfully add, subtract, multiply,
and reduce days, hours, and parts. Some may still require additional
drill on these operations. Design your own problems for more practice.
Have another student check your work, or see your instructor for
assistance.

                        ----------###----------

                              PROGRAM II

             CALCULATING THE DAY OF WEEK FOR MOLAD TISHRI
 

PERFORMANCE GOAL 2:

     Given a required Roman year, you will correctly calculate the day
of the week, hours, and parts for the molad Tishri of that Roman year.
This will be accomplished WITHOUT CHARTS AND TABLES.

     Why do you need to be concerned with the molad of Tishri? The
answer is that you must know when it occurs before you can determine
the date of the Festival of Trumpets. And all other holy days within a
Roman year (January-December) are ultimately referenced to that holy
day. The molad of Tishri is prerequisite to most calculations involving
the Hebrew calendar. Correct calculation of the molad of Tishri is thus
essential for determining what dates on the Roman calendar we commonly
use for God's Sacred Festivals to occur.

     Certain definitions and concepts need to become crystallized in
your mind:

     What is a molad?
     When is Tishri?
     What is a bench mark?
     How is time reckoned in the calculations?
     What is meant by the "advancement" of the molad?

Let's find the answers to these questions.

     What is the molad Tishri?

     TISHRI is the seventh month of the sacred calendar. The computed
time for the conjunction of the sun, moon, and the earth is called a
MOLAD, from the Hebrew MOLED (plural, MOLEDOTH). This word means
renewal, or rejuvenescence.

     Molad of Tishri is the computed time of the new moon of the month
of Tishri, which corresponds to September/October. As Tishri is also
the first month of the civil Hebrew year, the molad Tishri is also the
calculated astronomical commencement of the year.

     Another term which you will be using is bench mark. All this means
is a point of reference from which measurements can be made. Any known
molad (expressed as day of the month, day of the week, hours, and
parts, e.g., October 6, Sunday, 23 h, 204 p in 3761 BC) can serve as a
bench mark. The most practical choice for a bench mark, however, will
be the molad Tishri of year one in a 19 year cycle. 3761 BC is such a
year.

     In order to avoid a mental mix-up later, let's clarify how we
reckon time. Just what does an expression like 4 d  7 h  503 p mean?
Such an expression can be taken either of two ways: a) as an interval
of time b) a time in the week.

     Consider case a). Here, when you are speaking of a length of time,
you assume that you are starting from a reference point of 0 days, 0
hours, 0 parts. This is just the same as clocking a track runner on a
stop watch that starts ticking at the sound of the gun. A certain time
span is involved, figuring from a bench mark of 0 days, 0 hours, 0
parts.

     With case b), you are still reckoning time, but from a DIFFERENT
reference point. In the calendar calculations you are working in
Theological Research, the week begins at Sunday midnight. Sunday is
regarded as the first day of the week; midnight the zeroth hour, zero
parts:

          The week begins: Sunday: 1 d  0 h  0 p.

     An expression like 1 day 13 hours 0 parts MUST BY DEFINITION OF
THE STARTING POINT refer to Sunday, the 13th hour after midnight, or
Sunday 1 PM.

     Likewise, 1 day 13 hours 179 parts refers to a time slightly later
than 1 PM on Sunday.

     The reason why we arbitrarily begin Sunday as 1 day 0 hours 0
parts is so that there will be an exact coincidence with the days of
the week: 1 d is Sunday; 2 d is Monday; 4 d is Wednesday; 7 d is
Sabbath. So long as all the numbers are reduced, you merely look at the
number of days, and these correspond to the day of the week. (For the
same reason of SIMPLICITY, we begin the day with midnight instead of 6
PM so far as the CALCULATIONS are concerned. Since the bench mark is
expressed by this same reckoning, the final results will be exactly the
same.)

     By contrast, if we decided to define the beginning of the week,
Sunday, as the zero day, and Saturday sunset (say 6 PM) as the start of
Sunday, we would have the expression  0  d  0 h  0 p = 6 PM Saturday
evening. Then  1 d  13 h  179 p would have an entirely different
meaning, if it referred to a time in the week. 1 d would then be
Monday; 13 h  179 p would be slightly after 7 AM. Do you see how much
more complicated your work would then become?

     Here is another distinction that can help you understand the
difference in meaning between an interval of time, and a time in the
week:

   a) an interval of time:

     parts are added to the hours       are added to the days

   b) a time in the week:

     parts are added to the hours       WITHIN the day of the week.

     If 4 days 7 hours 503 parts refers to an interval of time, then
503 parts plus 7 hours is added to 4 days. Therefore the interval of
time goes as far as the 7th hour(and 503 parts) of the fifth day.

     If 4 days 7 hours 503 parts is to be taken as a point in the week,
then 503 parts plus 7 hours is WITHIN the 4th day of the week.

     Remember this difference in what is meant comes about by the way
the starting point is DEFINED, and for no other reason.

     During your calculation of the advancement of the molad over a
full number of weeks, you may come up with a number like 0 days 4 hours
and 71 parts. Be comforted by the fact that the expression is simply an
interval of time by the way Sunday midnight is defined.

     How can you relate a time interval to an expression of time during
a week?

     YOU MUST ADD AN INTERVAL OF TIME to the BENCH MARK before you can
determine a real day of the week. The bench mark will implicitly tell
you where the week begins. The bench mark for the year 3761 BC is
Sunday, the 23rd hour 204 parts. (We could have called that bench mark
Monday if we started the day at 6PM instead of midnight. But then we
would be confronted with a more complicated interpretation of what the
time expressions mean.)

     Now transform each of the following expressions to a) a time
interval b) a time during the week. Use this format:

a: _______ days, plus _______ hours _______ parts of the _______ day

b: _______ (day of the week), between _______ & _______ AM or PM

2.1  4 d   3 h  191 p
2.2  1 d  16 h  304 p
2.3  6 d   7 h    8 p
2.4  7 d  22 h    5 p
2.5  2 d  13 h  871 p

The answers are given below.

2.1  a)   4 days plus 3 hours 191 parts of the 5th day
     b)   Wednesday, between 3 & 4 AM

2.2  a)   1 day plus 16 hours 304 parts of the 2nd day
     b)   Sunday, between 4 & 5 PM

2.3  a)   6 days plus 7 hours 8 parts of the 7th day
     b)   Friday, between 7 & 8 AM

2.4  a)   7 days plus 22 hours 5 parts of the 8th day
     b)   Sabbath, between 10 & 11 PM

2.5  a)   2 days plus 13 hours 871 parts of the 3rd day
     b)   Monday, between 1 & 2 PM

     One particularly important time interval will occur throughout
your experience with the Hebrew calendar. In order to calculate the
molad Tishri, you will be working with two molads:

          * a known molad, such as 3761 BC -- a bench mark
          * the molad of the Roman year which you are determining

     The time interval between these two molads is the ELAPSED TIME.
Since you are dealing with the molad of Tishri in both the required
year and the bench mark, the elapsed time will be a whole number of
years, such as 4520 years, 1503 years, 38 years.
     Let's investigate another feature of the Hebrew calendar which we
can call MOLAD "ADVANCEMENT." Now you know that the MOLAD itself
doesn't really move, since the term is defined as the calculated
conjunction of the sun, moon, and the earth. We are using a figure of
speech very similar to sun "rise."

     Here's an illustration of what is meant by the advancement of the
molad. In 3761 BC, the molad Tishri was on Sunday  1 d  23 h  204 p. In
1980 AD the molad Tishri will be Tuesday  3 d  23 h  206 p. Although
thousands of years have elapsed over the time span, the APPARENT
"advancement" in the week of the second molad is only 2 days 0 hours
and 2 parts.

     Why does the molad occur on different days of the week? The length
of an average lunar month is  29 d  12 h  793 p. How much greater than
four full weeks is this?
 

        29 d  12 h  793 p
      -(28 d   0 h    0 p)
     -----------------------------
         1 d  12 h  793 p;  about a day and a half.

     The molads of two successive months cannot occur on the same day
of the week because of this EXCESS over 28 days. In one month, if the
molad were Monday 8 AM (2 d  8 h  0 p), the molad of the next month
would be:

         2 d   8 h     0p
       +(1 d  12 h  793 p)
     -----------------------------
         3 d  20 h  793 p,  or Tuesday, between 8 and 9 PM.

     Although the second molad occurred  29 d  12 h  793 p  after the
first one, the second molad was "displaced" WITH REFERENCE TO THE WEEK
by  1 d  12 h  793 p. Merely as a convenient label, we will refer to
that apparent shift as MOLAD ADVANCEMENT. But the molad doesn't move;
only the time of its occurrence IN THE WEEK apparently advances.

     The TOTAL MOLAD ADVANCEMENT is simply the EXCESS over the number
of full weeks in the elapsed time from the bench mark to the molad
Tishri of the desired Roman year.

     Just as monthly molads will occur on different days, the molad of
Tishri will advance in the week over the previous molad of Tishri. If
in three years the total advance were 13 days, the Molad would be 13
days later. But in terms of the day of the week, this would be 13-7, or
6 days later in the week.

     Now you will learn how to calculate the day of the week for the
molad Tishri.

     You will find it easier to understand how to determine the day of
the week for a given molad if the steps are explained first without the
mathematical details:

     In order to determine the day of the week for the molad of Tishri,
you must find the TOTAL ADVANCEMENT of the molad that occurs within the
time span involved from a known molad, or bench mark.

     What will make up that time span? From that bench mark, a certain
number of years will elapse to the particular year in question:

     molad of Tishri                                molad of Tishri
       (bench mark)                                 of required year
                              (elapsed time)
           *________________________________________________*
 

     Later on in this program, you will learn how to express elapsed
time as:

            a whole multiple of 19 year cycles,
     plus   the excess number of common years,
     plus   the excess number of leap years.

     Logically, the total advancement of the molad, or excess over full
weeks in the elapsed time, for the year in question can be found by
adding:

          the advancement due to whole multiples of 19 year cycles,
      +   the advancement due to the number of common years,
      +   the advancement due to the number of leap years.

     An example will clarify this. If the elapsed time is 156 years,
there are 8, 19 year cycles, 4 common years, and 2 leap years (you'll
see how this is done later). The total advancement of the molad will
be:

          8 times the advancement of one 19 year cycle
       +  4 times the advancement of one common year,
       +  2 times the advancement of one leap year.

     The final step is simply adding the total excess over full weeks
to whatever bench mark you started with. This figure will give you the
day of the week of the molad Tishri in question.

     Be sure that you understand the qualitative elements connected
with the advancement of the molad. A molad "advances" with respect to a
known molad because of the excess time in one average lunar month over
a full number of weeks. All you are doing is adding the total
advancement that occurs within the time interval from the bench mark to
the molad Tishri of the year in question. You are actually finding the
excess over the full weeks from the bench mark to the molad of the
required year.

     Your success at determining the day of the week of a required
molad impinges upon:

          a)   Correctly finding the ELAPSED TIME from a bench mark to
the required year.

          b)   Expressing the elapsed time in terms of multiples of 19
year cycles
                     +   common years in the remainder
                     +   leap years in the remainder

          c)   Calculating the molad "advancement" attributable to each
element of b), then adding these together, reducing as necessary.

          d)   Adding the reduced advance of the molad c) to the bench
mark.
 

ELAPSED TIME, 2A

     Three possibilities exist for the elapsed time from the bench mark
to the required year:

          a1)  Both years are AD dates.
          a2)  Both years are BC dates.
          a3)  One year is BC and the other is AD

(Although you might work backwards in time, this program will only
consider problems in which the bench mark is the EARLIER of the two
years.)

     a1: Bench mark and required year both AD dates. The elapsed time
is simply the difference between the two years. If the bench mark is
1845 AD and the required year is 1931, the elapsed time is:

                    1931    -    1845    =    86 years

If the bench mark is 895 AD and the required year is 1751, the elapsed
time is:

                    1751    -    895    =    856 years

     a2: Both years are BC dates. Many calculations use 3761 BC as a
bench mark. To be mathematically consistent, it is helpful to place a
negative sign ( - ) before all BC years. Since you will still be
subtracting in order to find the difference, the second number will
become positive -  ( - )  =  +. As you are primarily concerned with
years after 3761 BC, or -3761, the year in question will always be more
positive (closer to zero). As a check when both years are BC, expect
the elapsed time to be SMALLER than 3761 years. (Use only the "absolute
value" for the elapsed time, which means you can disregard the final
negative sign.)

Using 3761 BC as a bench mark, what is the elapsed time to 585 BC?

               -3761  -  (-585)  =  -3761  +  585  =  -3176

The elapsed time is 3176 years.

What is the elapsed time to 1486 BC?

               -3761  -  (-1486)  =  -3761  +  1486  =  -2275

The elapsed time is 2275 years.

     a3: Bench mark is BC and the required year is AD. 3761 BC is
frequently used as bench mark for AD years. Only one thing is really
different here. There is no year allotted for 0 AD or 0 BC.
Mathematically, the number system does have a 0. What do you do?

Graphically, the two systems look like:

Calendar:      5 BC   4 BC   3 BC   2 BC   1 BC   1 AD   2 AD   3 AD
Number Scale: -5     -4     -3     -2     -1      0      1      2

The number scale has one more place, a zero, than the calendar.
Therefore in time intervals that cross AD/BC, you must SUBTRACT ONE
from the answer you compute arithmetically. (The time span from 4 BC to
2 AD is only five years.) BE SURE YOU REMEMBER TO SUBTRACT ONE FROM THE
MATHEMATICAL COMPUTATION! But only when you cross over from BC to AD.

What is the time elapsed from 3761 BC to 1000 AD?

          -3761  -  +1000  =  -3761  -1000  =  -4761

The elapsed time, however, is 4761    -    1 year, or 4760 years.

What is the time span (elapsed time) to 1974 AD from 3761 BC?

        -3761 BC  -  (+1974)  =  -3761  -  1974  =  -5735

The elapsed time is 5735  -  1, or 5734 years. As a check, you should
be aware that in going from BC to AD, the elapsed time will be a larger
number (taken as an absolute value) than either the bench mark or the
required year.

Drill yourself on elapsed time calculations with the following
problems. Remember that if you are wrong here, all the rest of your
calculations w ill be off!

               Bench mark     Required year  Elapsed time

     2a.1        1845 AD         1971 AD
     2a.2        1883 AD         1945 AD
     2a.3        3761 BC         1442 BC
     2a.4        3761 BC            4 BC
     2a.5        3761 BC          721 BC
     2a.6        1861 BC          604 BC
     2a.7        3761 BC           31 AD
     2a.8        3761 BC         1859 AD
     2a.9        3761 BC         1982 AD

See problems 2b.1 to 2b.9 for the elapsed time.

EXPRESSING ELAPSED TIME, 2B

     Once you've determined the number of years between the bench mark
and the required year, you need to express that time in terms of the
Hebrew calendar.

     On a practical basis, 19 year cycles are convenient. Find the
number of 19 year cycles in the elapsed time, divide the elapsed time
by 19. The QUOTIENT is the number of 19 year cycles.

     Usually, however, this division will result in a remainder, a
number from 1 to 18. This remainder will tell you the number of years
elapsed in the next cycle.

     As you already know each 19 year cycle consists of 12 common years
and 7 leap years.

=====================================================================
     SINCE 142 AD (see footnote 1), the years in a cycle that are leap
years are:     3    6    8    11    14    17    19
=====================================================================

Be sure to memorize these numbers! (Of course, the years 1, 2, 4, 5, 7,
9, 10, 12, 13, 15, 16, and 18 are common.)

======================================================================
     Before 142 AD, the leap years were:  2  5  7  10  13  16  18
======================================================================

For any remainder you acquire after dividing the elapsed time by 19,
you:

     1)   Decide whether the required year is before 142 AD, or 142 AD
and after.
     2)   Count the number of leap years that fit in the remainder (or
you could count the common years).
     3)   The number of common years will be the remainder minus the
number of leap years.

For example, the elapsed time from 1845 AD to 1975 AD is 130 years.
This is 130/19 time cycles, or six 19 year time cycles plus 16 years
remainder.

The leap years for 1975 (after 142 AD) are 3, 6, 8, 11, 14. Five leap
years altogether. Since 1975 has 16 elapsed years and there are five
leap years thus far, there must be 16 - 5 or 11 common years.

--------------------------------------------------------------------
     (footnote 1) There is some evidence that an adjustment to the
Hebrew calendar may have taken place during the patriarchate of Simon
III (140-163). See Cyrus Adler, "Calendar, History of," in "The Jewish
Encyclopedia" (New York: Funk and Wagnalls, 1907), Vol. 3, p. 500.
--------------------------------------------------------------------

Here is another example. If the bench mark is 3761 BC and the required
year is 27 AD, the elapsed time is:

     -3761  -  (+27)  =  -3788 years; the elapsed time is 3787 years,
since you go from BC to AD.

      3787 / 19  =  199  19 year cycles, plus 6 elapsed years.

For 27 AD (before 142 AD), the leap years of the cycle are 2 and 5.
With two leap years, there must be  6  -  2, or 4 common years.

Practice expressing elapsed time in terms of 19 year cycles, the number
of leap years, and the number of common years. See problems 2a.1 to
2a.9.

          Elapsed   19 year   # of leap    # common
           time      cycles    years        years

2b.1        126 yrs
2b.2         62
2b.3       2319
2b.4       3757
2b.5       3040
2b.6       1257
2b.7       3791
2b.8       5619
2b.9       5742
 

Check answers against those below.

2b.1        6 cycles     4 leap    8 common
2b.2        3   "        1   "     4   "
2b.3      122            0         1
2b.4      197            5         9
2b.5      160            0         0
2b.6       66            1         2
2b.7      199            4         6
2b.8      295            5         9
2b.9      302            1         3

"ADVANCEMENT" OF THE MOLAD. 2c

     From your previous program (1A & 1B), you are equipped to find out
the required information regarding the advancement of the molad. Since
a lunar month has 29 days, 12 hours 793 parts, it is 1 day, 12 hours,
and 793 parts in excess of a full number of weeks. As you saw before, a
monthly molad (two successive months) advances 1 d  12 h  793 p.

     Knowing this, you can easily determine how much a molad "advances"
in a common year of 12 months, in a leap year of 13 months, or in a 19
year cycle of 235 months.

How much does the time of a molad "advance" in the week during a common
year?

     1 d   12 h  793 p   (the monthly "advancement",
                           or excess over 4 weeks)
                x 12          (number of lunar months in a common year)
     -----------------
     2     24   1586
     1     12    793
     -----------------                    6 days             8 hours
    12 d  144h  9516 p                 -------           ---------
                                   24 / 152 h      1080 / 9516 p
                                        144               8640
                                       -------            -------
    18 d    8 h  876 p   reduced          8 h              876 parts

     After 12 months, the molad "advancement" is 18 d  8 h  876 p.
Since full weeks will not affect the days of the week, you can divide
the reduced number of days by 7. So with respect to the week the molad
"advancement" for a common year is:

          4 d  8 h  876 p.

     You should notice an alternative way of arriving at the same
number. How much does a common year exceed the number of full weeks in
the year? Multiply the length of an average lunar month by 12 months:

     12  x  (29 d  12 h  793 p)  =  348 d  144 h  9516 p

Reduce this number: 354 d  8 h  876 p

Divide the reduced number of days by 7 to eliminate full weeks:

          4 d  8 h  876 p.

2c.1  Verify that an average leap year exceeds a full number of weeks
by 5 d  21 h  589 p.

2c.2  Verify that a 19 year cycle exceeds a full number of weeks by  2
d  16 h  595 p.

>From here on, you already are competent to handle the details of
multiplying the advancement of the molad, and then adding. For 4 BC (as
in 2a.4 and 2b.4) you will do the following:

     197  x (2 d  16 h  595 p)  molad advancement of 19 year cycles
       5  x (5 d  21 h  589 p)  molad advancement of leap years
       9  x (4 d   8 h  876 p)  molad advancement of common years

Multiplying and adding you will discover that this is:

          567 d  5228 h  254,404 p.

When reduced, and divided by seven (only the full reduced days are
divided by 7), the advancement of the molad over a week is:

          3 d  15 h  604 p.
 

ADDING REDUCED ADVANCEMENT OF MOLAD TO THE BENCH MARK, 2d

     The bench mark for 3761 BC is Sunday  23 h  204 p. This is
reckoning from midnight. As Sunday is the first day of the week, the
bench mark can be expressed as:

          1 d  23 h  204 p.

>From here on, you merely add the reduced advancement of the molad to
the bench mark. For 4 BC, this is:
 

              3 d  15 h  604 p
           +  1 d  23 h  204 p
          ----------------------------
              4 d  38 h  808 p
     or       5 d  14 h  808 p
 

     The fifth day of the week is Thursday, so the molad occurred on
Thursday, the 14th hour (2 PM), 808 parts.

So long as the final d, h, p, are reduced, you need only be concerned
(for now) with the first column.
 

2d.1  Verify that the molad for 721 BC is 5 d  7 h  364 p.

2d.2  Verify that the molad for 31 AD is 5 d  23 h  941 p.

2d.3  At this point, you should test yourself to be sure you can
fulfill the goal of program 2. Calculate the DAY OF THE WEEK of the
molad Tishri for 1996 AD without consulting this program. You'll need
to have memorized (or else work out again) the molad "advancement" for
a 19 year cycle, a common year, and a leap year, as well as remember a
bench mark.

Compare your calculations to the answer below, which is worked out in
detail.

Calculate the DAY OF THE WEEK of the molad Tishri for 1996 AD.

     -3761
     -1996
     -----------
      5757 yrs
        -1                302 cycles
     -----------         ----------
      5756 yrs      19 / 5756
                         57
                         --------
                           56
                           38
                          ------
                           18 elapsed yrs; 6 leap yrs; 12 common yrs
 
 

     2 d  16 h      595 p              5 d  21h    589 p
           x        302  (19 yr                 x    6   (leap
     -------------------- cycles)     ------------------  yrs)
     4 d  32 h     1190               30 d 126 h  3534 p
    60   480      17850
   -----------------------
   604 d 4832 h  179690 p                  4 d   8 h  876 p
                                                     x 12    (common
                                          ------------------  years)
                                          48 d  96 h  10,512p
 

        604 d       4832 h         179690 p
     +   30 d        126 h           3534 p
     +   48 d         96 h          10512 p
     ---------------------------------------
        682 d       5054 h         193736 p     total advancement
     ---------------------------------------
     +  218 d       +179 h
 

    128 weeks        218 d                   179 h
    -------         --------             -----------
7 / 900 d      24 / 5233 h         1080 / 193736 p          (reducing)
    xxx             xxx                    xxx
    ------          --------             ----------
      4 d              1 h                   416 p     reduced advance-
                                                       ment of molad

   + (1 d             23 h                   204 p)    bench mark
-----------------------------------------------------
      5 d             24 h                   620 p
      6 d              0 h                   620 p
=====================================================

The day of the week of molad Tishri in 1996 AD is Friday.
 

                        ----------###----------

                              PROGRAM III

         CALCULATING THE DAY OF THE MONTH OF THE MOLAD TISHRI
 

PERFORMANCE GOAL 3

     Without tables, you will correctly determine the day of the month
of the molad Tishri for the Roman years specified in this program.

     The procedure used to find the day of the month of the molad
Tishri parallels that of the day of the week calculation you already
learned in Program 2. Part of the work needed for the day of the month
calculation is ALREADY accomplished in the day of the week calculation!

     Let's review part of the day of the week calculation to see just
what operations are in common. You must have a required year and the
bench mark (assumed to be 3761 BC unless otherwise specified). From
these two years, you can determine elapsed time between them (read over
2a again if this is hazy). Be sure you remember to subtract 1 from the
total whenever you go from BC to AD. This is a common mistake!

     Next, you express the elapsed time in terms of 19 year cycles,
number leap years, and the number of common years (2b):

     *    Divide the elapsed time by 19.

     *    The remainder is the number of elapsed years in the 19 year
cycle of the required year. If the required year is 142 AD or after,
the intercalary years are 3, 6, 8, 11, 14, 17 and 19. (Before 142
AD, just subtract 1 from each of these numbers to obtain the
intercalary years of that cycle.)

     *    Count up the number of leap years that have occurred within
the cycle, including the last number. For example, if the remainder is
11, there are 4 leap years in the cycle.

     *    Subtract the number of leap years from the remainder, and you
will have the number of common years in that cycle.

     You have already done this much of the calculation in order to
determine the day of the week for the molad of Tishri. And you will use
this SAME information to find the day of the month. How is it applied?

     The answer rests in the basic difference between the Hebrew year
and the Roman (Julian) year. Common years in the Hebrew calendar have
353, 354, or 355 days, whereas a Roman year has 365 1/4 days. Compared
to the Julian year, the Hebrew common year falls short. A Hebrew
intercalary year (383, 384, or 385 days) is longer than the Roman year.

     Exactly how much will the Hebrew calendar trail the Roman calendar
in a common year of 12 months? The average common year is 12 times (29
d  12 h  793 p). This is 354 days, 8 hours and 876 parts.

            365 d   6 h    0 parts (average Julian year)
       -  ( 354 d   8 h  876 p     (average common year)
          --------------------------------
             10 d  21 h  204 p
 

In other words, the average common year of the Hebrew calendar is 10 d
21 h  204 p LESS than an average Julian year. For calculation purposes,
remember the number as  -10 d  -21 h  -204 p. This is the same as  -(10
d  21 h  204 p). If you cannot recall this number under the pressures
of a test, you should remember HOW it is found.

     How much LONGER is an average intercalary (or leap) year than the
average Julian year? To find the length of an average intercalary year,
multiply 13 months times  (29 d  12 h  793 p).

           383 d  21 h  589 p   (average leap year)
       -  (365 d   6 h    0 p)  (average Julian year)
          -----------------------------
            18 d  15 h  589 p
 

In an intercalary year, the Hebrew calendar EXCEEDS the Julian calendar
by  +18 d  +15 h  +589 p. The plus signs are carried in order to
minimize confusion. As you can see, this number is very easy to find.
 

     What about the 19 year cycle and the two calendars?

       29 d  12 h  793 p  (lunar months)  365 d  6 h  0 p  (Roman year)
                x  235 months per cycle          x   19 years
     -------------------                 ----------------
     6939 d  16 h  595 p                 6939 d 18 h  0 p
    (length of 235 lunar months)        (length of 19 Roman years)
 

How much shorter is the 19 year cycle of 235 lunar months than 19
Julian years?

           6939 d  18 h    0 p       19 Julian years
        - (6939 d  16 h  595 p)     235 average lunations
          ----------------------
                    1 h  485 p

Express this as  -1 h  -485 p. A 19 year cycle is one hour and 485
parts LESS than 19 Julian years.

     Let's summarize these three important numbers. Be sure you
understand exactly what each means!

---------------------------------------------------------------------

     0 d  -  1 h  - 485 p       19 year cycle is SHORTER than 19 Julian
                                   years.

  - 10 d  - 21 h  - 204 p       average common year is SHORTER than an
                                   average Julian year.

   +18 d  + 15 h  + 589 p       average leap year is LONGER than an
                                   average Julian year.

---------------------------------------------------------------------

     You use these three numbers quite like the three other numbers you
worked with in calculating the day of the week for the molad Tishri.
The only complication is that some of these numbers are negative, and
you must be certain that you do not overlook a negative number by
assuming it is positive. It's safer and surer to carry the signs along
through every step.

     Now let's illustrate a calculation of the day of the month for the
molad Tishri. Be aware of the fact that the years called for in this
program avoid certain complications, which will be explained in program
5.

     What is the day of the month of the molad Tishri in 1520 AD?
Proceed as you would for finding the day of the week.
 

  -3761   BC
 -(1520)  AD                                       277 cycles elapsed
-------------                                    -------
  -5281;  5281 - 1 =  5280 years elapsed     19 / 5280 years
                                                  xxx
                                                 -------
                                                    17;   3, 6, 8, 11,
                                                          14, 17 are
                                                          leap years.
                                                          6 leap years;
                                                      17  -  6  =  11
                                                       common years.

For the day of the month, you are determining how far the Hebrew
calendar lags or leads the Roman calendar:

      - 1 h     485 p   (lag per 19 yr cycle)   -10 d   -21 h   -204 p
          x     277 cycles                             x   11 com. yrs.
     --------------                            ------------------------
               3395                              10      21      204
              3395                              10      21      204
              970                              ------------------------
     --------------                            -110 d  -231 h  -2244 p
     -277 h - 134345 p

                                   + 18 d  +15 h  + 589 p
                                                  x   6 leap years
                                   -------------------------------
                                  + 108 d  +90 h  +3534 p

The amount the Hebrew calendar will LAG behind the Roman during the
elapsed time is the sum of the amounts trailed in the common years and
the 19-year cycles:

     -110 d    -231 h    -  2244 p
               -277 h    -134345 p
     ----------------------------------
     -110 d    -508 h    -136589 p   Amt. Hebrew calendar LAGS Roman
                                        calendar during elapsed time.

     +108 d    + 90 h    +  3534 p   Amt. Hebrew calendar leads Roman
                                        calendar during elapsed time.
     ---------------------------------
       -2 d    -418 h    -133055 p
 

                               -22 d                    -123 h
                             --------              ------------
                         24 / -541 h         1080 / -133,055 p
                               xxx                   xxx
                             --------              ------------
          -24 d                -13 h                    -215 p

     -24 d  -13 h  -215 p represents the TOTAL AMOUNT that the Hebrew
calendar trails the Roman calendar. (Just reduce the number to a
convenient negative form; full reduction isn't necessary.) NEVER divide
this number by 7! To find the day of the month, add the lag you have
calculated to the bench mark. Since September has 30 days, you can
express Oct. 6 as Sept. 36.
 

September  36    23 h  204 p       September  36    22 h  1284 p
         +(24 d -13 h -215 p)      or        -24 d -13 h  -215 p
-----------------------------      ------------------------------
                                   September  12  +  9 h +1069 p

The molad Tishri in 1520 AD was on September 12, just before 10 AM.

     The procedure for finding the day of the month for the molad
Tishri is almost exactly parallel to that for finding the day of the
week. To give you an overview of both calculations, here in schematic
form are the steps. Read this chart from left to right, as well as down
the page.
 

-----------------------------------------------------------------------
Molad Tishri             Day of the week          Day of the month
-----------------------------------------------------------------------
Bench mark & required    3761 BC - required yr    3761 BC - required yr
year. Going from BC      (-1)?                    (-1?)
to AD? Elapsed time      ---------------------    ---------------------
in years: (divide by
19)

number of 19 yr cycles   times (2d 16h 595p)      times    (-1h -485p)
number of common years   times (4d  8h 876p)       " (-10d -21h -204p)
number of leap years     times (5d 21h 589p)       " (+18d +15h +589p)
                         -------------------      ---------------------
                         Sum is the molad "ad-    Sum is the amount
                         vancement," or excess    that the Hebrew
                         over full weeks, in the  calendar lags (-) or
                         elapsed time. (Divide    leads (+) the Roman
                         the REDUCED days by 7.)  calendar. (Reduce as
                                                  necessary.)

Add to the bench mark    +(1 d 23 h 204 p)   Oct. 6 (Sept 36) 23h 204p

                                            [Corrections, in program 5]

Answer:                  (* day of week)          (* day of month)
                         ----------------------   ---------------------
-----------------------------------------------------------------------

     In most cases, you will determine the day of the week first, as
there is less chance for computational errors. This calculation will
give you a certain number of hours and parts besides the day of the
week.

     Is there any way of knowing that your calculations are correct?
Yes! The hours and parts for the day of the week of the molad Tishri
must be identical to the hours and parts for the day of the month. For
1520 AD, the example above, the hours and parts for the day of the week
are also 9h 1069p. Remember this rule for checking your work.

     Since the format involved in calculating the day of the month is
so very similar to the day of the week, a large amount of additional
practice will not be necessary. You should, however, work out a few
problems.

3.1 What is the day of the month of the molad Tishri for 1492 AD?

3.2 What is the day of the month of the molad Tishri for 28 AD?

The problems are partially worked out for you below.

3.1  1492 AD is 5252 elapsed years. This is 276 19 year cycles, and 8
elapsed years. Therefore there are 3 leap years (3, 6, 8) and 5 common
years. The molad was on September 21, 19 hours and 1011 parts. (This
was a Friday, in case you want to check that calculation, too.)

3.2  28 AD is 3788 elapsed years. 3788 years is 199 19 year cycles and
7 years. In 7 elapsed years, there are 3 leap years (2, 5, 7) and four
common years. (If you noticed that these multipliers for the leap and
common years are the same as in 3.1, you saved yourself some work!) The
molad was on October 7, 8 hours 760 parts. (This was a Thursday.)

Now that you have almost completed this program, you should feel
confident of your ability to calculate the day of the month for the
molad Tishri. If you experienced a bit of difficulty with problems 3.1
and 3.2, you may want to work out 1520 AD again, and then compare each
of your steps with the example already worked above.

3.3  As a final self-test, without consulting the program or your
notes, determine the day of the month of the molad Tishri for 1448 AD.
The answer is worked out in detail below.

Calculate the day of the month of the molad Tishri for 1448 AD:
 

     -3761
     -1448                               274 cycles
     -------                           -------
      5209;  5208 elapsed years    19 / 5208
                                        xxx
                                       -------
                                          2 years; no leap years
                                                  2 common

                                   -10 d  21 h  -204 p
                                                 x 2 common
                                   --------------------
              -1 h    -485 p       -20 d  42 h  -408 p
                       274 cycles
             ----------------
               4      1940
              7      3395
             2       970
          -------------------
            -274 h -132890 p
     -20 d   -42 h    -408 p
     ------------------------
     -20 d  -316 h -133298 p  (no leap years)
 

                             18 h                 -123 h
                          --------            ------------
          -20 d       24 / -439 h       1080 / -133298 p
          -18 d             xxx                 xxx
          ------          ------              ------------
          -38 d              -7 h                - 458 p
     Sept  36              + 23 h                + 204 p (bench mark)
           ----------------------------------------------------------
     Sept  -2              + 16 h                - 254 p
     Sept  -2              + 15 h                  826 p
     ==========
 

     Sept    0    =    August 31
     Sept  - 1    =    August 30
     Sept  - 2    =    AUGUST 29   day of the month
                       =========

                        ----------###----------

                              PROGRAM IV

                 USING TABLES TO FIND THE MOLAD TISHRI

PROGRAM GOAL 4

     Given a table of reduced days; hours, and parts, for the Hebrew
calendar, you will correctly calculate the day of the week and the day
of the Roman month for the molad Tishri of selected years. Use of the
table will considerably shorten the time needed.

     Having worked out the problems in the first three programs of this
series, you may have decided that Hebrew calendar calculations are more
tedious than difficult.

     Yes, some of the arithmetical operations tend to be time
consuming. Perhaps you feel that you can calculate the molad Tishri
quite well, but you'd prefer having some kind of a desk top computer
just to save time and frustration! Not that all the steps are too
involved for you to do yourself; only the lengthy multiplication and
division.

     Finding the elapsed time is just a quick subtraction or addition
operation. Expressing the elapsed time in terms of 19 year cycles still
isn't demanding. The real hang-up comes in the multiplication of the 19
year cycles, the leap years, and the common years, right?

     Most of that step, so far as the multiplication is concerned, can
be eliminated by using a table of reduced days, hours, and parts. You
will be able to calculate the molad Tishri in less than half the time
previously required!

     Examine part I of the chart included in this program. On the left
side of the page as you read it is a table marked "19 YEAR TIME
CYCLES." Toward the bottom of the page are two other tables
"INTERCALARY YEARS" and "COMMON YEARS." (We'll return to the other
table on part I a little later.)

     As you suspect, each of these three tables will replace the
multiplication operations you did before in order to find the excess
over a number of full weeks, or the molad "advancement." Now you can
read a reduced number from the table very conveniently!

     Suppose you have a problem in which the elapsed time is 200   19
year cycles, three leap (intercalary) years, and five common years.
What will be the excess over full weeks?
 

               200  19 year cycles:     5 d  22 h 200 p
                 3  leap years:         3 d  16 h 687 p
                 5  common years:       0 d  20 h  60 p
               ----------------------------------------
               Total:                   8 d  48 h 947 p
                    Excess over full
                    weeks:              2 d   0 h 947 p
 

     Of course, most of your calculations of elapsed time will involve
intermediate values of 19 year cycles, which are not directly on the
first table. What do you do with 189 cycles, 315 cycles, and the like?
Just add them with the units you already have. If, in the example
above, we had 276 19 year time cycles instead of 200, you would add the
molad "advancement" for 70 cycles and for 6 cycles:
 
 

                    200  19 year cycles:  5 d  22 h  200 p
          276        70  19 year cycles:  6 d   6 h  610 p
          cycles      6  19 year cycles:  2 d   3 h  330 p
                      3  leap years:      3 d  16 h  687 p
                      5  common years:    0 d  20 h   60 p
                    ---------------------------------------
                    Total:               16 d  67 h 1887 p

     You can add these numbers in less time than it takes to multiply
276 x (2 d 16 h 595 p). Notice that you can perform all your addition
in one step.

     For the 19 year cycles, it may be easier in some problems to do a
subtraction of two numbers in the table rather than an addition of
three. The excess over full weeks of 297 19 year cycles can be found
either way:

                    add    200:      5 d  22 h  200 p
                            90:      4 d   1 h  630 p
                             7:      4 d  19 h  925 p
                    -----------------------------------
                    297 cycles:     13 d  42 h 1755 p
                    reduced:         0 d  19 h  675 p
 

                    subtract 300:    1 d  21 h  300 p (1 d 20 h 1380 p)
                              -3:   -1 d  -1 h -705 p
                    -----------------------------------
                                     0 d  19 h  655 p

     Now practice using the table to find the day of the week of the
molad Tishri for:

4.1  1520 AD. The problem is worked out below.

          3761 BC
          1520 AD                                  277 cycles
          -----------                            -------
          5281;     5280 elapsed years       19 / 5280
                                                  xxx
                                                 -------
                                                    17 yrs: 3, 6, 8,
                                                       11, 14, 17
                                                       6 leap
                                                       11 common

Using the table:
               200 cycles:      5 d  22 h  200 p
                70     "        6 d   6 h  610 p
                 7     "        4 d  19 h  925 p
                 6 leap:        0 d   9 h  294 p
                11 common:      6 d   0 h  996 p
               -----------------------------------
               Total:          21 d  56 h 3025 p
               Excess over full
                    weeks:      2 d  10 h  865 p
               bench mark    +( 1 d  23 h  204 p)
               ------------------------------------
               Reduced          3 d  33 h 1069 p
                                4 d   9 h 1069 p

Molad Tishri:  Wednesday 1520 AD
     The first time through a calculation with the chart took more time
than you will need later. But we can even go through a problem faster
by using the table on the first page called "ELAPSED YEARS IN ONE 19
YEAR CYCLE."

     This table combines the leap years and the common years of a 19
year cycle together, both for dates before 142 AD and for those after.
Once you divide the elapsed time by 19, you can match the remainder
directly without figuring leap years and common years separately. If
your remainder is 12 (for a year after 142 AD), the excess over full
weeks would be 2 d  12 h 724 p.

4.2  Re-calculate the day of the week for the molad Tishri for 1520 AD
using the combined table. The answer is below.

          3761 BC
          1520 AD                             277 cycles
          ----------                        -------
          5281; 5280 years              19 / 5280 years
                                             xxx
                                            -------
                                               17 elapsed years

>From the chart, part I:

          200  cycles:          5 d     22 h   200 p
           70      "            6 d      6 h   610 p
            7      "            4 d     19 h   925 p
           17  elapsed years:   6 d     10 h   210 p
          -------------------------------------------
          Total                21 d     57 h  1945 p
          bench mark            1 d     23 h   204 p
                         ----------------------------
                               22 d     80 h  2149 p
          Reduced:              4 d      9 h  1069 p

Molad Tishri: Wednesday.

     Notice that you need not reduce until the last step. If you want,
it's even possible to add the benchmark after the elapsed years of a
cycle-without sub-totaling first. Once you thoroughly understand the
concepts involved in calculating the molad Tishri, you can make these
economies in your work.

     (Incidentally, if you choose to add the bench mark along with the
numbers from the table, your answer -- after reduction -- may take the
form of 0d   xx h   xxx p. What day of the week is 0 d? Just add 7 to 0
d, and you will have the real day -- the sabbath. When you are working
with the days of the week, "7" is the "additive complement" of numbers
from -6 to 0. There's nothing mysterious here, just a mathematical
"law".)

     Now look at part II of the Hebrew calendar chart. This section
will assist you in calculating the day of the month. The tables are
very much like those of part I. The negative numbers represent the
amount the Hebrew calendar lags behind the Roman calendar for a given
unit of time. The positive numbers indicate that the Hebrew calendar
leads the Roman.

     Because of the different signs involved, you'll find it easier to
total the negative numbers together before combining the positive. For
example, how much does the Hebrew calendar trail the Roman after 276
19 year cycles plus 8 elapsed years?
 

          200 cycles:    -12 d     -  1 h     - 880 p
          70 cycles:     - 4 d     -  5 h     - 470 p
          6 cycles:      - 0 d     -  8 h     - 750 p
          --------------------------------------------
          276 cycles:    -16 d     - 14 h    - 2100 p
          8 elapsed yrs. + 2 d     - 12 h    +  747 p
          --------------------------------------------
          Total:         -14 d     - 26 h    - 1353 p

     All you need do now is add the bench mark. The Hebrew calendar is
usually behind the Roman, so the total will be mostly negative numbers.
The parts or hours COULD be positive in some problems. Watch your
SCRIBAL ACCURACY!

     Sept 36      23 h      204 p  (bench mark)
         -14 d   -26 h    -1353 p
     -----------------------------

Borrowing:

     Sept 35      45 h     2364 p
         -14 d   -26 h     1353 p
     -----------------------------
     Sept 21      19 h     1011 p

     Whenever you are making a calculation, it will be faster to use
the combined table instead of the individual tables of intercalary
years and elapsed years. But you can take either option.

---------------------------------------------------------------------
If you find that calculations of the day of the month are different
from those of the day of the week, be sure that you used the right
table for the right number!
---------------------------------------------------------------------

4.3  Calculate with the use of the chart the day of the month of molad
Tishri for 1520 AD. The answer is below.

          1520 AD
          3761 BC                             277 cycles
          ------------                      -------
          5281; 5280 years              19 / 5280
                                             xxx
                                            -------
                                               17 elapsed years

>From the chart, part II:

     200 cycles:      -12 d   - 1 h   - 880 p
      70 cycles:      - 4 d   - 5 h   - 470 p
       7 cycles:      - 0 d   -10 h   - 155 p
     --------------------------------------------
                     - 16 d   -16 h   -1505 p
     17 years        -  7 d   -20 h   + 210 p
     ---------------------------------------------
                     - 23 d   -36 h   -1295 p
     bench mark  Sept. 35      45 h    2364 p  (borrowing)
     ---------------------------------------------
                 Sept. 12 d     9 h    1069 p

     You can set up both the day of the week and the day of the month
calculations side by side to save space if you like.

4.4  Test yourself on a complete calculation of the molad Tishri, day
of the week and the Roman date, for 1000 AD. Consult the chart in an
efficient manner.

          1000 AD
          3761 BC                             250 cycles
          -----------                       -------
          4761; 4760 years              19 / 4760
                                             xxx
                                            -------
                                               10 elapsed years

          Day of the week                    Day of the Roman month

     200 cycles:   5 d   22 h   200 p        -12 d  -  1 h  -  880 p
      50 cycles:   1 d   11 h   290 p        - 3 d  -  0 h  -  490 p
                                             -------------------------
  10 elapsed yrs.  6 d    6 h   339 p        -15 d  -  1 h  - 1370 p
  bench mark:      1 d   23 h   204 p        -20 d  -  6 h  +  339 p
  -----------------------------------        -------------------------
         Total:   13 d   62 h  1333 p        -35 d  -  7 h  -  931 p
       Reduced:    1 d   15 h   253 p   Sept  36    + 22 h  + 1284 p
                                             -------------------------
                                               1 d    15 h     253 p

     The hours and the parts agree.
     In 1000 AD the molad Tishri was Sunday, Sept. 1, 15 h 253 p.

     By using the Hebrew calendar chart, notice how much less space on
the page a complete calculation of the molad Tishri now takes. And
easier, isn't it!

-----------------------------------------------------------------------
                         THE HEBREW CALENDAR
        Tables of Reduced Days, Hours, and Parts for 19 Year
         Time Cycles, Intercalary Years, and Common Years.

        I. Advancement of the Molad Over a Full Number of Weeks

                         19 YEAR TIME CYCLES
                    Elapsed   Excess over full weeks
                    Cycles
                    -------   ----------------------
                      1            2d   16h   595p
                      2            5     9    110
                      3            1     1    705
                      4            3    18    220
                      5            6    10    815
                      6            2     3    330
                      7            4    19    925
                      8            0    12    440
                      9            3     4   1035
                     10            5    21    550
                     20            4    19     20
                     30            3    16    570
                     40            2    14     40
                     50            1    11    590
                     60            0     9     60
                     70            6     6    610
                     80            5     4     80
                     90            4     1    630
                    100            2    23    100
                    200            5    22    200
                    300            1    21    300

                        ----------###----------

                           INTERCALARY YEARS

                 Elapsed Yrs.  Excess over full weeks
                 ------------  ----------------------
                      1            5d   21h  589p
                      2            4    19    98
                      3            3    16   687
                      4            2    14   196
                      5            1    11   785
                      6            0     9   294
                      7            6     6   883

                        ----------###----------

                ELAPSED YEARS IN ONE 19 YEAR TIME CYCLE
 

     Elapsed        Before 142 AD     |    142 AD and after    Elapsed
      Years    Excess over full weeks | Excess over full weeks  Years
     -------   ---------------------- | ---------------------- -------
        1           4d   8h   876p    |      4d   8h   876p       1
        2           3    6    385     |      1   17    672        2
        3           0   15    181     |      0   15    181        3
        4           4   23   1057     |      4   23   1057        4
        5           3   21    566     |      2    8    853        5
        6           1    6    362     |      1    6    362        6
        7           0    3    951     |      5   15    158        7
        8           4   12    747     |      4   12    747        8
        9           1   21    543     |      1   21    543        9
       10           0   19     52     |      6    6    339       10
       11           5    3    928     |      5    3    928       11
       12           2   12    724     |      2   12    724       12
       13           1   10    233     |      6   21    520       13
       14           5   19     29     |      5   19     29       14
       15           3    3    905     |      3    3    905       15
       16           2    1    414     |      0   12    701       16
       17           6   10    210     |      6   10    210       17
       18           5    7    799     |      3   19      6       18

                        ----------###----------

                             COMMON YEARS

               Elapsed Yrs.   Excess over full weeks
               ------------   ----------------------
                    1              4d   8h   876p
                    2              1   17    672
                    3              6    2    468
                    4              3   11    264
                    5              0   20     60
                    6              5    4    936
                    7              2   13    732
                    8              6   22    528
                    9              4    7    324
                   10              1   16    120
                   11              6    0    996
                   12              3    9    792

-----------------------------------------------------------------------
     II. Time Differences
 

                          19 YEAR TIME CYCLES

               Elapsed Cycles          Time Difference
               --------------      -----------------------
                      1              - 0d    - 1h  - 485p
                      2              - 0     - 2   - 970
                      3              - 0     - 4   - 375
                      4              - 0     - 5   - 860
                      5              - 0     - 7   - 265
                      6              - 0     - 8   - 750
                      7              - 0     -10   - 155
                      8              - 0     -11   - 640
                      9              - 0     -13   -  45
                     10              - 0     -14   - 530
                     20              - 1     - 4   -1060
                     30              - 1     -19   - 510
                     40              - 2     - 9   -1040
                     50              - 3     - 0   - 490
                     60              - 3     -14   -1020
                     70              - 4     - 5   - 470
                     80              - 4     -19   -1000
                     90              - 5     -10   - 450
                    100              - 6     - 0   - 980
                    200              -12     - 1   - 880
                    300              -18     - 2   - 780

                        ----------###----------

                           INTERCALARY YEARS

               Elapsed Inc.
                   Years         Time Difference
               ------------   --------------------
                    1         + 18d   +15h   +589p
                    2         + 37    + 7    + 98
                    3         + 55    +22    +687
                    4         + 74    +14    +196
                    5         + 93    + 5    +785
                    6         +111    +21    +294
                    7         +130    +12    +883

                        ----------###----------

                ELAPSED YEARS IN ONE 19 YEAR TIME CYCLE

     Elapsed   Before 142 AD       142 AD and after    Elapsed
      Years    Time Difference     Time Difference     Years
     -------   ---------------     ----------------    -------
        1      -10d -21h -204p     -10d -21h -204p        1
        2      + 8  - 6  +385      -21  -18  -408         2
        3      - 3  - 3  +181      - 3  - 3  +181         3
        4      -14    0  - 23      -14    0  - 23         4
        5      + 5  - 9  +566      -24  -21  -227         5
        6      - 6  - 6  +362      - 6  - 6  +362         6
        7      +13  -15  +951      -17  - 3  +158         7
        8      + 2  -12  +747      + 2  -12  +747         8
        9      - 9  - 9  +543      - 9  - 9  +543         9
       10      +10  -17  + 52      -20  - 6  +339        10
       11      - 1  -15  +928      - 1  -15  +928        11
       12      -12  -12  +724      -12  -12  +724        12
       13      + 7  -20  +233      -23  - 9  +520        13
       14      - 4  -17  + 29      - 4  -17  + 29        14
       15      -15  -15  +905      -15  -15  +905        15
       16      + 4  -23  +414      -26  -12  +701        16
       17      - 7  -20  +210      - 7  -20  +210        17
       18      +11  - 5  +799      -18  -17  +  6        18

                        ----------###----------

                             COMMON YEARS

               Elapsed Comm.
                  Years              Time Difference
               -------------       -------------------
                     1             - 10d  -21h  - 204p
                     2             - 21   -18   - 408
                     3             - 32   -15   - 612
                     4             - 43   -12   - 816
                     5             - 54   - 9   -1020
                     6             - 65   - 7   - 144
                     7             - 76   - 4   - 348
                     8             - 87   - 1   - 552
                     9             - 97   -22   - 756
                    10             -108   -19   - 960
                    11             -119   -17   -  84
                    12             -130   -14   - 288

                        ----------###----------
 

     as they are often different; e. g. 1 positive and 2 negative.

            - signifies that the Hebrew calendar is behind,
                    or trails, the Julian calendar.

           + signifies that the Hebrew calendar is ahead of,
                    or leads, the Julian calendar.

----------------------------------------------------------------------

                               PROGRAM V

       MAKING ROMAN LEAP YEAR AND JULIAN / GREGORIAN CORRECTIONS

PERFORMANCE GOAL 5

     For any required Roman year, AD or BC, you will correctly make the
necessary adjustments for:

          a) the Roman leap year / common year pattern
          b) the conversion from the Julian to the Gregorian calendar

     In your day of the month calculations of the molad Tishri.

     By actively working through the first four programs, you've
learned how to calculate the molad Tishri for the specified years. Now
you will apply two corrections to the DAY OF THE MONTH calculations.
This will extend your ability to find the molad of Tishri to virtually
any Roman year required, whether AD or BC. Keep in mind that these
corrections affect ONLY the day of the month calculations! The day of
the week part of your work needs no adjustment.

     The first correction involves the length of a Roman year. On a
calendar, a Roman year has either 365 days (common year) or 366 days
(leap year). In your calculations for the day of the month, you used
the average length of a Roman year, 365 1/4 days. How do you make
allowance for the difference?

     You add six hours to the molad (day of the month) for every year
after a Roman leap year:

          If the required Roman year is leap, add 0 hours.
          If the required Roman year is one year after a leap year, add
6 hours.
          If the required Roman year is two years after a leap year,
add 12 hours.
          If the required Roman year is three years after a leap year,
add 18 hours.

     (Don't become confused by what a "leap year" means. A Hebrew leap
year has 13 months; a Roman leap year has 366 days. The context will
tell you what applies.)

     How can you know if the required Roman year is leap or common?
Simply divide the year by four and note the remainder: 10 AD divided by
4 gives a remainder of two; 51 BC divided by 4 gives a remainder of
three; 1977 AD divided by 4 leaves a remainder of one.

     For AD years, the remainder numerically corresponds to the Roman
leap year/common year pattern:

     A remainder of 0 signifies that the required Roman year is leap.
        "           1         "                   one after a leap.
        "           2         "                   two after a leap.
        "           3         "                   three after a leap.

     BC years have a different pattern of remainders. Since 4 AD is a
leap year, 1 AD is three years before a leap year. 1 BC is a leap year,
too, being four years before 4 AD. Four years before 1 BC is 5 BC, a
leap year. And 9 BC is a leap year. Then 8 BC is one year after a Leap
year; 7 BC is two years after; 6 BC is three after. If you divide these
years by 4, you can find the remainder that corresponds to a leap year
(9 divided by 4 leaves a remainder of 1), a year after a leap year,
etc. This pattern of remainders from 9 BC to 6 BC will be valid for
years further back into antiquity.
 

     The chart below summarizes the remainder patterns for both BC and
AD Roman years.

     Roman leap year corrections (dividing the required year by 4)
=======================================================================
AD:

 If the remainder is 0,  add no hours to the day of month calculations
          "      1   6 hours
          "      2  12 hours
          "      3  18 hours
BC:
 If the remainder is 1,  add no hours to the day of month calculations

          "      0   6 hours
          "      3  12 hours
          "      2  18 hours
-----------------------------------------------------------------------

     To insure that you can apply this correction to the day of the
month, indicate how many hours you would add for each of the following
years.

          5.1  1520 AD             5.10  1917 BC

          5.2  1974 AD             5.11     4 BC

          5.3  1983 AD             5.12   971 BC

          5.4  1871 AD             5.13  1181 BC

          5.5  1699 AD             5.14  1020 BC

          5.6    31 AD             5.15  1984 AD

          5.7    33 AD             5.16  1020 AD

          5.8   142 AD             5.17  2001 BC

          5.9  1486 BC             5.18  2001 AD

The answers appear below.

     5.1   0 hours            5.7    6 hours           5.13   0 hours
     5.2  12 hours            5.8   12 hours           5.14   6 hours
     5.3  18 hours            5.9   18 hours           5.15   0 hours
     5.4  18 hours            5.10   0 hours           5.16   0 hours
     5.5  18 hours            5.11   6 hours           5.17   0 hours
     5.6  18 hours            5.12  12 hours           5.18   6 hours
 

     When you are checking your calculations for the molad of Tishri,
you may find that the day of the month calculation differs from the day
of the week by six hours, twelve hours, or eighteen hours. Here's what
has happened: You forgot to make the Roman leap year correction in the
day of the month calculation! Divide the Roman year by 4 and inspect
the remainder on EVERY calculation involving the day of the month.

                        ----------###----------

     The second correction to the day of the month calculation of the
molad Tishri concerns the corresponding Gregorian calendar date of a
day on the Julian calendar. By understanding the reasons for the change
from the Julian calendar to the Gregorian, you will have no difficulty
in performing this correction.

     The Julian calendar was named after Julius Caesar; the Gregorian
calendar after Pope Gregory XIII. Both calendars are "Roman." The
Gregorian calendar is what you use every day.

     When did the Roman calendar, based upon an average yearly length
of 365 1/4 days, come into use? The answer is 45 BC. With the aid of
the Egyptian astronomer Sosigenes, Julius Caesar completely revised the
previous lunisolar calendar, which had drifted badly with respect to
the seasons. To effect the reform, "46 BC" had 445 days assigned to it
in order to correct for all the previous errors. That year was very
appropriately called the "year of confusion!" In 45 BC the vernal
(spring) equinox occurred on March 25.

     The Julian calendar wasn't without its faults, however. The
average Julian year was eleven minutes and fourteen seconds LONGER than
a "tropical year." (A tropical year is measured from one vernal equinox
to the next.) After 128 years the Julian calendar had an extra day,
compared to an equal number of tropical years.

     By the time of the famous Council of Nicea in 325 AD, the Julian
calendar was about three days behind the tropical year. This meant that
the vernal equinox was several days "early" on the Julian calendar.
Accordingly, the churchmen based their rules for the date of Easter on
the spring equinox falling on March 21 of the Julian calendar. It had
been March 25 in 45 BC.

     Towards the end of the Counter-Reformation in the sixteenth
century, the spring equinox had "crept back" to about March 11. To
alleviate the problem, Pope Gregory reformed the Julian calendar by
deleting ten days from the month of October 1582: The day after October
4 officially became October 15. So after 1582 the spring equinox
shifted back to March 21--where it had been during the time of
Constantine the Great. (Of course, the equinox never shifted; the
calendars did the moving!)

     Pope Gregory also invoked a new rule concerning Roman leap years.
The Julian calendar considers every fourth year as having 366 days. To
shorten the new Roman calendar by three days in 400 years, the Pope
declared that century years NOT EVENLY DIVISIBLE BY 400 would remain
COMMON (no February 29).

     Therefore, 1700 AD, 1800 AD, and 1900 AD, which are not evenly
divisible by 400, were common years according to the Gregorian calendar
rules. By the old Julian calendar, they would have been leap years.

     Instead of the eleven minute error in the average Julian year, the
average Gregorian year is only 26 seconds too long.

     How do you convert a Julian date into a day on the Gregorian
calendar? Just add the TOTAL DAYS that have been dropped from the
Julian! Before 1582 AD no correction is needed, as all the Roman dates
are understood to be Julian. But after 1582 AD, you must add at least
ten days to the Julian day of the month calculation for the molad
Tishri.

     Bear in mind that 1600 AD was a leap year in both the Julian and
the Gregorian calendars. The difference between the calendars remained
ten days until 1700. The Gregorian calendar omitted February 29 that
year (because the year wasn't evenly divisible by 400), while the
Julian retained the extra day. From 1700 to 1799, the Julian calendar
was eleven days behind the Gregorian since that was the total number of
days dropped.

     In the same manner, from 1800 to 1899 you must add twelve days to
the Julian date to find the corresponding Gregorian day. During the
1900's and 2000's, you add thirteen days.

     How many days will you add to your day of the month calculations
of the molad of Tishri to convert from the Julian calendar to the
Gregorian calendar for each of the following years?   (Before 1582 AD,
simply respond "0 d".)

     5.19 1520 AD

     5.20 1601 AD

     5.21 1798 AD

     5.22 1914 AD

     5.23 1851 AD

     5.24 1666 AD

     5.25 1583 AD

     5.26 1984 AD

     5.27 2001 AD

     5.28 2145 AD

     5.29 1979 AD

     5.30 1712 AD

The answers appear below.

     5.19 + 0 d          5.25 +10 d

     5.20 +10 d          5.26 +13 d

     5.21 +11 d          5.27 +13 d

     5.22 +13 d          5.28 +14 d

     5.23 +12 d          5.29 +13 d

     5.24 +10 d          5.30 +11 d

                                *  *  *

     Neither of the corrections to the day of the month calculation of
the molad Tishri is complicated. However, you must remember to perform
them whenever the Roman year calls for such adjustments. The last
problem in this program will challenge you to put together all the
calendar skills you have learned thus far.

5.31   What is the day of the week and the date of the Roman month for
the molad Tishri in 2055 AD? (You may use the chart of reduced
numbers.) This problem is worked out in detail for you on the next
page.

What is the day of the week and the date of the Roman month for the
molad of Tishri in 2055 AD?
 

A.   The ELAPSED TIME is:     - 3761
                              - 2055
                              -------
                              - 5816 - subtract 1 going from BC to AD:
                                          5815 years.

B.   5815 years is 5815 / 19 nineteen year cycles.

                          306
                         -------
                    19 / 5815      306 cycles and the first year of the
                         57        next cycle have elapsed.
                         ------
                          115
                          114
                         ------
                            1
 

C. THE DAY OF THE WEEK FOR THE MOLAD TISHRI:

     From the tables, find the advancement of the molad.

     300  19-year cycles:          1 d  21 h   300 p
       6  19-year cycles:          2 d   3 h   330 p
       1 year of next cycle:       4 d   8 h   876 p
                                   ------------------
                                   7 d  32 h  1506 p
          Reducing this:                +1 h -1080 p
                                   ------------------
                                   7 d  33 h   426 p
                                 + 1 d -24 h
                                   ------------------
          The advancement is:      1 d   9 h   426 p   over full number
                                                       of weeks.
          Add the advancement to
          the bench mark:        +(1 d  23 h   204 p)
                                   ------------------
                                   2 d  32 h   630 p

          This reduces to:         3 d   8 h   630 p

The molad was on the third day of the week, Tuesday.
 

D. THE DAY OF THE ROMAN MONTH:

>From the tables, find how far behind the Roman calendar the Hebrew
calendar is:

     300   19-year cycles:    -18 d  - 2 h  - 780 p
       6   19-year cycles:    - 0 d  - 8 h  - 750 p
       1 year of next cycle:  -10 d  -21 h  - 204 p
                              --------------------------
                              -28 d  -31 h  -1734 p
     The benchmark is:      Sept. 36  23 h    204 p

"Borrow" 2  x  1080 parts, and one day:

                            Sept. 35  45 h   2364 p

Add the time difference in the calendars to the benchmark:

                            +(-28 d  -31 h -1734 p)
                    --------------------------------
                            Sept.  7  14 h   630 p

Two corrections must be made, that of the ROMAN leap year, and the
Julian / Gregorian:

          513
         -------
     4 / 2055
         20
         -------
           5             3 years after a Roman leap year means
           4             you must add 18 HOURS.
           ---
           15
           12
           ---
            3

During the 1900's, the correction to the Julian calendar is 13 days.
Since 2000 is evenly divisible by 400, the correction during the 21st
century is STILL 13 days.
 

          Sept. 7   14 h  630 p
                   +18 h           Roman leap year correction
               13 d                     Julian / Gregorian correction
          --------------------------
         Sept. 20   32 h  630 p
Molad
Tishri:  Sept. 21    8 h  630 p    parts and hours agree
                                   with day of week

                        ----------###----------

                              PROGRAM VI

          APPLYING THE POSTPONEMENT RULES TO FIND TISHRI ONE

     PERFORMANCE GOAL 6A: Given the molad Tishri for a required year,
you will correctly determine the day of the week and the day of the
month of the Feast of Trumpets, Tishri 1, by applying from memory the
four postponement rules explained in this program.

Example: In 1987, the molad of Tishri will be:

     September 23 Wednesday (4 d)  3 h  77 p

What is the date for the Feast of Trumpets?

     Answer: September 24 Thursday (by rule two)

     PERFORMANCE GOAL 6B: Without consulting notes, you will correctly
explain (in a brief paragraph for each rule) why each postponement for
Tishri 1 is important for the Hebrew calendar.

     PERFORMANCE GOAL 6A: After correctly calculating both the day of
the week and the day of the month for the molad of Tishri the next step
is to find the date of Tishri 1, the Feast of Trumpets. You will
analyze the time of the molad to see how four postponement rules affect
the Feast of Trumpets.

     At the outset, you should understand that a conjunction of the
earth, moon, and sun takes place completely apart from man's doings.
The MOLAD CANNOT BE POSTPONED BY HUMAN ENACTMENTS! Tishri 1, the civil
New Year in the Hebrew calendar, is what is postponed.

     Here are the four postponement rules, prefaced by a general
statement of the case where there is no postponement:

     When the molad Tishri occurs at a time of the week that's
unaffected by the four postponement rules, the Feast of Trumpets is on
the SAME DAY as the molad.

     Rule one: When the molad of Tishri occurs AT NOON OR LATER (12 h
0 p or more in your calculations), the Feast of Trumpets is postponed
until the next day.

     Rule two: When the molad of Tishri OR a postponement occurs on a
Sunday, Wednesday, or Friday, the Feast of Trumpets is postponed one
day, to a Monday, Thursday, or Sabbath, respectively.

     Rule three: When the molad of Tishri of a COMMON YEAR is on a
Tuesday, at or after (3 d)  3 h  204 p the Feast of Trumpets is
postponed to a Wednesday, and by Rule two, further postponed
to a Thursday.

     RULE FOUR: When the molad of Tishri of a COMMON year IMMEDIATELY
FOLLOWING an intercalary year occurs on a Monday, at or after (2 d)  9
h  589 p the Feast of Trumpets is postponed to a TUESDAY.

     You should take notice that the maximum postponement of Tishri 1
is two days. Also realize that the order of these rules is significant.
They are easiest to apply in the numerical order above. Rule one
governs all afternoon time periods, so rules three and four ONLY AFFECT
A PORTION OF THE MORNINGS.

     You will quickly discover that rules one and two are by far the
most frequently used, both individually and together -- one, two, or
one and two. And years where no postponement of Tishri 1 is required
are rather common, too.

     This means, of course, that rules three and four are quite
infrequent, especially the last one. Rule three has rule two "built
in", since it is a very specific case. Therefore, rule three and rule
four are always separately used. Whenever rules one and two apply,
either separately or in combination, you know in advance that rules
three and four will not be involved. All this speeds up your use of
these rules considerably.

     Before you see examples of each rule applied, one more thing needs
to be explained. How do you know when the year in question is common,
and when does it immediately follow a leap year?

     Remember how you determined elapsed time by adding (or
subtracting) the required year from the bench mark? Well, the year in
question is the year AFTER the number of elapsed years. The distinction
between the terms "elapsed years" and "required year" is quite similar
to your age. All through your 21st year of life, your age is twenty!

     What do you do to find which year of the cycle is a required year?
Add 1 to the remainder you already found when you divided the elapsed
years by 19. This new remainder will be the number of the year in the
cycle. If the remainder for elapsed years is 10, the required year is
year 11 of the l9-year cycle.

     You will recall that for the years 142 AD (handwritten note: 256
AD --  Dr. Hoeh correct date) and after, the intercalary years are 3,
6, 8, 11, 14, 17, 19. The years immediately following these years are
the ones you are concerned with for rule four: 4, 7, 9, 12, etc. All
the years in the cycle which aren't intercalary are common.

     Whenever you are working with years earlier than 142 AD, be sure
to use the proper intercalary years, which are one year earlier than
the present cycle: 2, 5, 7, 10, 13, 16, 18. The year after these leap
years will then apply for rule four.

          Now you will learn how to analyze the molad Tishri to apply
the postponement rules.

1492 AD: Molad Tishri was September 21, Friday  6 d  9 h  1011 p.

     19 h  1011 p is after 12 h  0 p; RULE ONE postpones to the
Sabbath. The Sabbath is a permissible day; no further postponement.

          Feast of Trumpets was September 22, Sabbath.

1584 AD: molad Tishri was September 5, Wednesday  4 d  2 h  852 p.

     2 h  852 p is before 12 h  0 p; rule one not involved. Wednesday
is a forbidden day; RULE TWO applies.

          Feast of Trumpets was September 6, Thursday.

1615 AD: molad Tishri was September 22, Tuesday 3 d  20 h  804 p.

     20 h  804 p is after 12 h  0 p; RULE ONE postpones to Wednesday.
Wednesday is a forbidden day; RULE TWO re-postpones to Thursday.

          Trumpets was September 24, Thursday.

1632 AD: molad Tishri was September 14, Tuesday, 3 d  6 h  1014 p.

     6 h  1014 p is before 12 h  0 p. Rule one doesn't apply. Tuesday
is a permissible day. Rule two doesn't apply. 6 h  1014 p is after 3 h
204 p. Rule three could be involved. Is 1632 a common year?
     The elapsed time from 3761 BC is 5392 years to 1632 AD. Then the
year in question is the 5393rd year, or the 16th year of a cycle after
283 full cycles. This is a common year. RULE THREE does apply.

          Tishri 1 is September 16, Thursday.

841 AD: molad Tishri was September 19, Monday, 2 d  11 h  735 p.

     Rules one, two, and three, don't apply. The molad is on a Monday,
and 11 h  735 p is after 9 h  589 p. Is 841 AD a common year
immediately after a leap year? From 3761 BC to 841 AD is 4601 years;
the required year is the 4602 year. This is 242 19-year cycles plus 4
years of the next. This is a common year immediately following a leap
year. RULE FOUR applies.

          Trumpets was September 20, Tuesday.

1910 AD: molad Tishri was October 4, Tuesday, 3 d  0 h  61 p.

     0 h  61 p is before 12 h  0 p; rule one doesn't apply. Tuesday is
a permissible day; rule two doesn't apply.  0 h  61 p is before 3 h
204 p; rule three doesn't apply. Rule four can't apply to Tuesday. No
postponement.

          Trumpets is October 4, Tuesday.

     As you can see, only a few seconds are needed to check a molad of
Tishri for applicable postponements. Don't under-estimate the
importance of doing this operation correctly, however! All of the other
Holy Days are derived from the date of Tishri one!

     Practice applying the postponement rules to the following molads.
The correct dates for the Feast of Trumpets are listed on the next
page, along with the postponement rules which are needed.

6a.1  1264 AD September 22, Monday 2 d  13 h  351 p

6a.2  1255 AD September 3, Friday 6 d  3 h  95 p

6a.3  1259 AD September 18, Thurs. 5 d  15 h  865 p

6a.4  2001 AD September 17, Monday 2 d  22 h  106 p

6a.5  2008 AD September 30, Tuesday 3 d  1 h  1057 p

6a.6  2014 AD September 24, Wednesday 4 d  8 h  339 p

6a.7  1984 AD September 25, Tuesday 3 d  11 h  976 p

6a.8  1985 AD September 14, Sabbath 7 d  20 h  772 p

6a.9   462 AD September 10, Monday 2 d  1 h  511 p

6a.10  496 AD September 23, Monday 2 d  10 h  644 p

6a.11  134 AD October 5, Monday 2 d  23 h  343 p

6a.12  118 AD October 2, Sabbath 7 d  21 h  1009 p

6a.13  588 BC September 27, Tuesday 3 d  3 h  209 p

6a.141  953 BC September 12, Sunday 1 d  12 h  4 p

Answers on following page:
 
 

     Answers:                                     Rule

     6a.1      September 23, 1264 AD; Tuesday       1

     6a.2      September 4, 1255 AD; Sabbath        2

     6a.3      September 20, 1259 AD; Sabbath       1, 2

     6a.4      September 18, 2001 AD; Tuesday       1

     6a.5      September 30, 2008 AD; Tuesday       ---

     6a.6      September 25, 2014 AD; Thursday      2

     6a.7      September 27, 1984 AD; Thursday      3

     6a.8      September 16, 1985 AD; Monday        1, 2

     6a.9      September 10, 462 AD; Monday         ---

     6a.10     September 24, 496 AD; Tuesday        4

     6a.11     October 6, 134 AD; Tuesday           1

     6a.12     October 4, 118 AD; Monday            1, 2

     6a.13     September 29, 588 BC; Thursday       3

     6a.14     September 13, 953 BC; Monday         1
 

                    *    *    *    *    *    *
 

PERFORMANCE GOAL 6B: You do not need to understand the reasons behind
the postponement rules in order to correctly apply them. However, your
appreciation of the Sacred calendar will be enhanced by grasping the
purpose of each rule.
 

WHY RULE ONE, NOON OR AFTER POSTPONEMENTS?

     Whenever the molad of Tishri occurs at noon or after (12 h   0 p),
Tishri one is postponed to the next day (at least). But how did the
molad come to be associated with noon? Rule one points back to the
initial formulation of the Hebrew calendar -- in the days of Seth,
according to Josephus. God intended that the heavenly bodies would
intrigue man to study their movements carefully. "Let there be lights
in the firmament of the heaven to divide the day from the night; and
let them be for signs, and for seasons, and for days, and for years"
(Gen. 1:14).

     As you may have observed, the sun, moon and stars rise and set
each day. But the sun rises each day about four minutes later with
respect to the stars. It has a proper motion of its own, independent of
the stars. This motion is not due to the daily rotation of the earth on
its axis, which gives the illusion that the sun moves westward each
day. The apparent path of the eastward journey of the sun through the
stars, known as the "ecliptic", is due to the earth's annual orbital
revolution.

     The earth is tilted 232 degrees on its axis. By studying the
diagram below, you can see that the plane of the earth's equator is
inclined 232 degrees from the plane of the earth's orbit. Astronomers
call the projection of the earth's equator into space the "celestial
equator".

---------------------
(NOTE: To view the diagram mentioned above, see the file HEB-CAL1.TIF
in the Images\OtherWCG directory.)
---------------------

     Seasons occur because the earth's orbital plane (the plane of the
earth's orbit) is not coincident with the plane of the earth's equator.
The vernal equinox takes place when the apparent northward moving sun
crosses the celestial equator. It again intersects the celestial
equator when the sun passes below the celestial equator moving
southward--at the time of the autumnal equinox. On the days of the
equinoxes, the day and night periods are equal.

     Consider the next diagram, which is a closeup of the vernal
equinox. The moment of the equinox occurs when the center of the sun
crosses the celestial equator. But the sun's apparent diameter is 1/2
degree; therefore the TRAILING EDGE of the sun is still 1/4 degree
behind the equinoctial point.

---------------------
(NOTE: To view the diagram mentioned above, see the file HEB-CAL2.TIF
in the Images\OtherWCG directory.)
---------------------

     How long will it take for the trailing edge of the sun to pass the
point of the vernal equinox? The sun's eastward progress along the
ecliptic is about 1 degree per day (since the earth revolves 360
degrees around the sun in about 365 days). In 24 hours the sun moves 1
degree; in 12 hours it moves 1/2 degree; in 6 HOURS it moves 1/4
degree.

     Six hours before sunset is 12 noon. Unless the equinox occurs
BEFORE noon, the sun's trailing edge will not have passed the celestial
equator by sunset! When the equinox occurs at noon or later, Sol is
still a winter sun. The first day of spring is therefore assigned to
the following day.

     This is one reason why noon became a logical demarcation point for
time in astronomical matters. Noon is a stable observation point for
time, irrespective of the observer's latitude. (The time of sunrise and
sunset, but not noon, vary considerably during the course of a year,
especially in the extreme latitude.) From earliest known times until
1925, astronomers had traditionally used noon as a reference point for
the day. Thus noon became in antiquity a limit point not only for the
equinox, but also for the molad.

     Just as noon arbitrated the first day of spring and the first day
of fall, it served a similar function with the assigned day of the
molad -- that is, the molad or conjunction of the moon had to have a
natural and arbitrary limit, in this case noon.
 

WHY RULE TWO, FORBIDDEN DAYS?

This postponement rule prevents Holy Days from falling on a Sunday
(during the fall) and the Passover occurring at awkward times:

     If Trumpets could occur on a Wednesday, the Day of Atonement,
Tishri 10, would fall on a Friday, the preparation day for the Sabbath!
And the Passover would also be observed Saturday night, a most
difficult time.

     If Trumpets could occur on a Friday, the Day of Atonement would be
on a Sunday, the day after the Sabbath.

     If Trumpets could occur on a Sunday, then the first day of the
Feast of Tabernacles, as well as the last Great Day would be on a
Sunday.

WHY RULE THREE, THE TUESDAY-COMMON YEAR POSTPONEMENT?

As you recall, the maximum length of a common year in the Hebrew
calendar is 355 days. Without this rule, a common year might have 356
days!

Anytime in the morning of a Tuesday, 3h   204 p is affected by this
rule. Why this particular moment?

     Start with Tuesday        3 d  3 h  204 p
     Add an average        + ( 4 d  8 h  876 p)   the excess over full
     common year         -----------------------  number of weeks
                               7th 11 h 1080 p

     This number is the same as the seventh day 12 hours and no parts.
This means that the next molad Tishri would occur on a Sabbath at noon.
But rule one says you must postpone to a Sunday, and rule two says to
re-postpone until a Monday.

     From Tuesday until Monday is six days. The full number of weeks in
a common year (50) gives 7 x 50 = 350 days. So that year would have 356
days -- if rule three didn't intervene.
 

WHY RULE FOUR, THE MONDAY-COMMON YEAR FOLLOWING LEAP YEAR POSTPONEMENT?

     The minimum number of days an intercalary year can have is 383
days. If rule four weren't in effect, some leap years would have only
382 days. An average leap year has 5 d  21 h  589 p over a full number
of weeks, which is 54.

     Suppose that a common year just after a leap year began on the
same day as the molad, Monday 2 d  9 h  589 p. When would the preceding
leap year have begun?

     Monday                2 d   9 h  589 p
     average leap yr.    -(5 d  21 h  589 p) excess over full number of
                         ------------------- weeks.
                         - 3 d -12 h

     -3 d  -12 h is the same as -4 d  +12 h. Whenever you are working
with negative days of the week, you merely add 7 d to find out what day
of the week you are actually on. -4 d  +7 d is the 3 d of the week, or
Tuesday. The molad of the leap year thus occurred on a Tuesday at noon.
But rule one says that this must be postponed to a Wednesday, and by
rule two, re-postponed to a Thursday.

     If the leap year began on a Thursday and ended on a Monday, there
would be four days over the full number of weeks. 7 x 54 weeks is 378
days. 378 days plus 4 days is only 382 days; less than the minimum.

     Without these postponement laws, the sacred calendar would be in a
perpetual state of confusion. Holy Days would fall on a Sunday. The
lengths of years would be irregular. Calendar reformers would be
tempted to tamper with the sacred calendar more often. Picture the
difficulty of a deacon trying to keep a Sabbath Day holy while
frantically making last minute preparations for the Passover ceremony!

     But all that turmoil is avoided by four very simple and easily
applied postponement rules. Instead of the Sacred Festivals being
subordinate to the Hebrew calendar the latter serves the Holy Days.

                        ----------###----------

                              PROGRAM VII

        COUNTING THE DAYS OF THE WEEK AND THE DAYS OF THE MONTH

PERFORMANCE GOAL 7A:

     You will count forward or backward a specified length of time from
a given day of the week and correctly determine the new day of the
week.

For example:

     What day of the week is 164 days before Thursday?
     Answer: Monday.
 

PERFORMANCE GOAL 7B:

     Given the date and the day of the week for any one day in a Roman
or Hebrew month, you will correctly indicate:

     a) The day of the week for any other given date in that month, or
     b) the dates for any specified day of the week in that month.

For example:

     a) If the 13th of a month is on a Friday, what day of the week
would the 4th be?
     Answer: Wednesday.

     b) What are the dates for Tuesday in a month when a Monday in that
month is on the 9th?

     Answer: 3, 10, 17, 24, (31).
 

COUNTING THE DAYS OF THE WEEKS 7A

     Counting the days of the week is so simple that you're probably
inclined to use "finger-calculations" quite often! Despite the apparent
lack of complexity, however, mistakes can easily creep in. Wouldn't you
prefer a less embarrassing technique than finger-counting to explain
why a Holy Day occurs when it does? A more dignified demonstration is
possible!

     All of the Sacred Festivals of God are anchored to Tishri one. For
example, the Day of Atonement is ten days after Trumpets. Passover is
164 days before. Accurate determination of the day of the week of the
Festivals depends on correct counting procedures. Basic arithmetic is
all that's needed.

     As you recall from Program 3, Calculating the day of the week of
the molad Tishri, multiples of full weeks do not affect the final day
of the week involved. Only the excess, or remainder, is significant.
Just as seven days from Monday is still a Monday, 147 days (twenty one
weeks) before or after Monday is still a Monday.

     In the same manner as Program 3, equate the days of the week with
the numbers 1 to 7. Sunday is the first day, Wednesday is the fourth
day, the Sabbath is the seventh day.

     Days AFTER a reference day are ADDED to the numerical equivalent
of the reference day. Days BEFORE the reference day are SUBTRACTED from
the numerical equivalent. You will find it much easier if you take out
full multiples of weeks before you add or subtract.

     Here are some examples. On what day of the week will Atonement
occur when Trumpets is on a Monday? Atonement (Tishri 10) is nine days
after Trumpets, or one week and two days later. Monday is the second
day of the week.

          2  +  2  =  4  The fourth day of the week is Wednesday.

     On what day of the week will Passover occur when Trumpets is on a
Sabbath? Passover is 164 days before Trumpets. Divide 164 by 7, and you
can express the time interval as 23 weeks and 3 days.

          7  -  3  =  4  The fourth day is Wednesday. (It's observed
Tuesday night.)

     What happens when you want to find the day of Passover if Trumpets
were on a Monday? Arithmetically, the problem is simply 2  -  3  =  -1.
What day of the week does this negative number indicate? Simply ADD 7
to any negative number in these calculations of the day of the week:

          -1  +  7  =  6 The sixth day of the week is Friday.

     Here is an alternative way of expressing the same reasoning. First
indicate the total time in terms of full weeks and days over a full
week As an illustration, Passover is always 164 days before Trumpets.
This is the same as 23 weeks and 3 days before. If Trumpets occurs on
Tuesday, 23 weeks before the Tuesday of Trumpets is another Tuesday.
What is three days before Tuesday? One day before is Monday; two days
before is Sunday; three days before Tuesday is the Sabbath. Passover is
on a Sabbath, observed Friday evening.

     Pentecost always occurs on a Sunday because of inclusive
reckoning. Leviticus 23:15 states that Pentecost is counted "from
[beginning with] the morrow after the Sabbath, from the day that ye
brought the sheaf of the wave offering ..." The wavesheaf offering was
performed on Sunday, the day after the weekly Sabbath. With a Sunday
the first day, seven full weeks (or forty-nine days) takes one to the
fiftieth day, again on a Sunday.

     By counting inclusively, 50 days is seven weeks. If you divide
seven weeks by seven, you have no remainder. Sunday is the first day of
the week, so arithmetically you have 1  +  0  =  1, or Sunday, as you
started.

     Practice finding the day of the week in the following problems.
Set them up in terms of a simple arithmetical expression.

7a.1  What is 17 days after a Monday?

7a.2  What day is 6 days before Tuesday?

7a.3  What is 50 days after a Saturday.

7a.4  On what day does Passover occur if Trumpets is on a Tuesday?

7a.5  What day is 53 days before Thursday?

7a.6  If Passover is on a Friday (Thursday evening), when does
Atonement occur?

The answers are on the next page.
 

7a.1  17 days = 2 weeks, 3 days. Monday is the second day of the week.
                    2 + 3 = 5; Thursday.

7a.2  Tuesday is the third day of the week. 3 - 6 = -3. Add 7 to change
                    this to a real day: -3 + 7 = 4; Wednesday

7a.3  50 days = 7 weeks, one day. Sabbath is the seventh day. 7 + 1 =
                    8. Divide by seven and look at the remainder: 1;
                    Sunday.

7a.4  164 days = 23 weeks, three days. Tuesday is the third day. 3 - 3
                    = 0. Convert this to a real day by adding seven:
                    0 + 7 = 7; Sabbath.

7a.5  53 days is 7 weeks, 4 days. Thursday is the fifth day. 5 - 4 = 1;
                    Sunday.

7a.6  Passover and Trumpets are separated by 23 weeks, 3 days.
Atonement is nine days after Trumpets, or one week, two days later.
Passover is on the sixth day. Then Trumpets is on:

          6 + 3 = 9. Eliminate the seven (9-7): 2; Monday.
     When Trumpets is on Monday, Atonement will be:
          2 + 2 = 4; Wednesday.
 

COUNTING THE DAYS OF THE MONTH, 7B

     Hebrew months have either 29 or 30 days. Most months on a Roman
calendar contain 30 or 31 days. As you recall from the form of most
printed calendars, the same days of the week are placed over top one
another.

     For example, take a month of 30 days whose first day is Sunday. It
will appear:

               Sun  Mon  Tue  Wed  Thu  Fri  Sat
                 1    2    3    4    5    6    7
                 8    9   10   11   12   13   14
                15   16   17   18   19   20   21
                22   23   24   25   26   27   28
                29   30

     Take particular notice of the sequence in the columns (up and down
the page). The Tuesday column contains all the days of the month which
fall on Tuesday. They are, in this case, 3, 10, 17, 24.

     What number separates these days of the month? Seven. One week
from the third day of the month is 7 days later, or 3 + 7 days into the
month. One week after the 10th is 10 + 7, or the 17th, etc. Learn to
count by sevens for numbers up to 31.

     Not every month will begin with the first day of the week, of
course. You still can utilize the sequence of numbers separated by
seven no matter what day of the week the month commences.

7b.1 What is the sequence of days of the month which occur on the
     Sabbath when the first Sabbath is on the 2nd?

7b.2 What is the sequence of days of the month that fall on Monday when
     the first day of the month is a Friday?

7b.3 If one of the Tuesdays of the month is the 22nd, what would be the
     other days of the month for Tuesdays?

7b.4 What are the days of the month for the Sabbath in a month where
     one of them is on the 16th?

7b.5 The month of AB has 30 days. The 10th of Ab is a Thursday. On what
     days of the month will the Mondays occur?

7b.6 The month of Thammuz has 29 days. The 6th of Ab is a Sabbath. On
     what days of the month will the Wednesdays occur?

7b.7 If the 14th of a month is on Wednesday, what day of the week would
     the 26th be?

7b.8 If the 22nd of the month is on Sunday, what day of the week would
     the 10th be?

The answers to these problems are below.

7b.1   2, 9, 16, 23, 30 are Sabbaths.

7b.2   Friday, the 6th day of the week, is the first of the month. Then
          Monday, three days after Friday, is the fourth. The Mondays
          are: 4, 11, 18, 25.

7b.3   The 29th is the last Tuesday in the month. To find the others,
          count backward "by sevens" from the 22nd:  15, 8, 1.

7b.4   16, 23, 30; 9, 2. These are the Sabbaths.

7b.5   10th = Thursday; Monday is 4 days later, or the 14th. 7, 14, 21,
          28 are the Mondays.

7b.6   Sabbath = 6th of the month. Wednesday is three days earlier in
          the week, or the 3rd: The Wednesdays in Thammuz (in this
          case) are 3, 10, 17, 24.

7b.7   Two weeks after the 14th is the 28th, a Wednesday. The 26th is
          two days before the 28, so it is a Monday.

7b.8   Two weeks before the 22nd is the 8th, a Sunday. The 10th will be
          two days later, or Tuesday.

                        ----------###----------

                             PROGRAM VIII

             DETERMINING THE DATES OF THE ANNUAL FESTIVALS

PERFORMANCE GOAL 8:

     Given the day of the week and the Roman date for the Feast of
Trumpets, you will correctly determine the day of the week and the day
of the Roman month for each of the other annual Festivals in the Roman
year. These Festivals are listed in Leviticus 23.

     One of the most practical aspects of studying the Hebrew calendar
is understanding the layout of Sacred Festivals. Obviously, if the
Western World were using the Hebrew calendar for routine business
affairs, there would be no need for transforming the dates of Trumpets,
Atonement, Passover, etc., to the Roman calendar. But since this isn't
the case, one must know what day of the Roman calendar each Holy Day
corresponds.

     Program 8 builds upon the calculation skills you have learned in
program 7. Take time to review the previous program as is necessary for
you.

     In order to understand the relationship of the dates of the Holy
Days, let's summarize the calendrical information given in Leviticus 23
Reference      Festival                 Hebrew Date
=======================================================================
Lev. 23:5      Passover            Nisan 14; 164 days before Tishri 1
       :6-7    1st day of
               Unleavened Bread    Nisan 15
       :8      7th day of
               Unleavened Bread    Nisan 21
       :15-16  Pentecost           50 days beginning with the Sunday of
                                   the wavesheaf offering, (which is
                                   the day after the [a] regular weekly
                                   Sabbath) [ NOT AN ANNUAL SABBATH ]
                                   [ THE SUNDAY WHICH IS ] during the
                                   Days of Unleavened Bread. (Always a
                                   Sunday.)

                                   [ See the WWN 5-11-87 & GN 6-74 for
                                   comments in brackets ]

       :24     Trumpets            Tishri 1
       :27     Atonement           Tishri 10 (9 days after Trumpets)
       :34-35  1st day of
               Tabernacles         Tishri 15
       :36     Last Great Day      Tishri 22; (the "8th day" of the
                                   Festival, or 7 days after Tishri 15)
-----------------------------------------------------------------------

     One of the first questions you will have is this: How do you know
that Nisan 14, Passover, is 164 days before Tishri 1? The answer is
quite simple: the intervening months are always the same length, no
matter whether the year is leap or common. Nisan has 30 days; Zif
(Iyar) 29; Sivan 30; Tammuz 29; Ab 30; Elul 29. Then comes Tishri.
After the 14th day, Nisan has 16 days remaining in the month. The next
five months, Iyar through Elul have 147 days (29 + 30 + 29 + 30 + 29).
One more day to Tishri 1. Add 16 + 147 + 1, and you have 164 days.

     Remember the "count by seven" pattern that separates the same day
of the week in any month? You learned in Program 7 that days 1, 8,15,
22, and 29 of a month are the same day of the week. Notice that three
of the four Holy Days in the fall season occur on the SAME DAY OF THE
WEEK!

     All the fall Holy Days occur in the month of Tishri, on the 1st,
10th, 15th, and 22nd. Once you determine the day of the week of
Trumpets, you know immediately the day of the week of the first day of
Tabernacles and the Last Great Day. They're all the same! And Atonement
is simply two days later in the week than Trumpets.

     Another convenient feature of the Holy Days is that Tishri 1 can
fall only on a Monday, Tuesday, Thursday or Sabbath. (Recall
Postponement Rule 2 in Program 6?) This means that in any Roman year,
the Holy Days will have one of these four patterns based upon what day
of the week the Feast of Trumpets occurs. You have a "Monday pattern",
a "Tuesday pattern", a "Thursday pattern", and a "Sabbath pattern".
Once you understand these four patterns -- and they need NOT be
memorized, as you will see! -- you can list the day of the week of ALL
the Sacred Festivals for any given year in about 30 seconds. Yes, it's
that simple!

     Here is a brief diagram to show you how all the Holy Days in a
Roman year hinge upon the day of Tishri 1. The Hebrew civil year is
reckoned from Tishri to Tishri, so in that sense, two Hebrew years are
involved when you specify all the Holy Days in one Roman year.

           How the Annual Holydays Are Governed By Tishri 1

              HEBREW YEAR               HEBREW YEAR
  Tishri 1                  Tishri 1                Tishri 1
 (Trumpets)                (Trumpets)              (Trumpets)
      |                         |                        |
      |                         |                        |
--//--|                         |                        |
      |-------------------------|------------------------|
      |             |           |           |            |
      |---       Passover       |---     Passover        |---
      |   |                     |  |                     |  |
      | Atonement               |  Atonement             | Atonement
      | Tabernacles             |  Tabernacles           | Tabernacles
======================================================================
               |                        |                          |
            January                   January                   January
               |        ROMAN YEAR      |      ROMAN YEAR          |
               |                        |                          |
 

     How do you lay the Holy Days out on the Roman Calendar? Since you
determine Tishri l first, it's a good policy to work with the fall
festivals first, then the Passover and Days of Unleavened Bread, and
finally Pentecost. Of course, the day of the week for Pentecost is
always on a Sunday because of the way God defined the time for
observing that Holy Day. Nevertheless, you still need to find the date
for Pentecost.

     Take the "Sabbath pattern" as an illustration of the days of the
week. Your reasoning will go something like this:

     For this year, Trumpets (Tishri 1) is on a SABBATH
     Atonement is 9 days later, or two days later in the week: MONDAY
     Feast of Tabernacles begins on the 15th of Tishri: SABBATH
     The Last Great Day is Tishri 22: SABBATH

     (Or, in more abbreviated fashion, think of Tishri 1, 10, 15, 22
corresponding to Sabbath, Monday, Sabbath, Sabbath.)

     Passover is 164 days before Trumpets, or three days earlier in the
week: WEDNESDAY
     The first day of Unleavened Bread is the next day: THURSDAY
     The last day of Unleavened Bread is Nisan 21, one week after
Passover: WEDNESDAY

     (In a less verbose manner, think Nisan 14 is 3 days earlier in the
week than Trumpets. Then Nisan 14, 15, 21 correspond to Wednesday,
Thursday, Wednesday.)

     Pentecost is a SUNDAY.

     If you are still uncertain about how this pattern of days is
thought out, please read Program 7 again. It will become much simpler
once you understand the basic concepts of counting days that are
explained in that program.

     Now practice on the four patterns yourself. You might want to do
them more than once just to impress the thinking process more fully in
your mind. The four patterns of Holy Days are extremely important! Work
each pattern independently from the others -- for your own benefit.

8.1  What is the "Thursday pattern" of Holy Days? In other words, what
are the days of the week for each of the annual festivals when Trumpets
is on a Thursday?

8.2  What is the "Monday pattern" of Holy Days?

8.3  What is the "Tuesday pattern" of Holy Days?

8.4  What is the "Sabbath pattern" of Holy Days?

     The answers are given below. (Don't try to memorize them UNLESS
you can first figure them out yourself!)

8.1  Tishri 1 is on Thursday. Tishri 1, 10, 15, 22 correspond to
          Thursday, Sabbath, Thursday, Thursday.
     Passover is 3 days earlier in the week than Trumpets: Monday.
     Nisan 14, 15, 21 correspond to Monday, Tuesday, Monday.
     Pentecost is on Sunday.

     On an examination, of course, you should actually list these dates
along with the Holy Day:

     Passover, (Nisan 14 ), Monday
     1st day of Unleavened Bread, (Nisan 15), Tuesday
     Last day of Unleavened Bread, (Nisan 21), Monday
     Pentecost, Sunday Trumpets, (Tishri 1), Thursday
     Atonement, (Tishri 10), Sabbath 1st day of Tabernacles, (Tishri
          15), Thursday
     Last Great Day, (Tishri 22),Thursday

8.2  Tishri 1 is on Monday. Tishri 1, 10, 15, 22 correspond to Monday,
          Wednesday, Monday, Monday.
     Passover is three days earlier in the week: Friday.
     Nisan 14, 15, 21 correspond to Friday, Sabbath, Friday.
     Pentecost is on Sunday.

8.3  Tishri 1 is on Tuesday. Tishri 1, 10, 15, 22 correspond to
          Tuesday, Thursday, Tuesday, Tuesday.
     Passover is three days earlier in the week than Trumpets: Sabbath.
     Nisan 14, 15, 21 correspond to Sabbath, Sunday, Sabbath.
     Pentecost is on Sunday.

8.4  See the example given previously in this program for the answer.

     Now that you can easily determine the day of the week for each of
the annual Holy Days, the final task is to specify the day of the month
on a Roman calendar for each Festival.

     The Roman dates of the fall festivals are very easy to determine
if you simply work with the "seven pattern" of days in a month -- that
you learned in Program 7. All you are concerned with are the equivalent
Roman dates to Tishri 1, 10, 15, and 22.

     You will either be given the day of the week and the day of the
Roman month for Trumpets, or else you will calculate the molad Tishri
for the required year yourself. The known correspondence between the
Hebrew calendar and the Roman calendar for one day provides the key to
determining the other dates.

     Imagine a Hebrew calendar for the month of Tishri, but with most
of the days except for 1, 10, 15, and 22 deleted.

                              TISHRI

                            1
                           (8)  (9)  10
                           15
                           22

     Suppose that Tishri 1 in a particular year occurred on September
7. To find the dates of the other fall Holy Days, lay out an
abbreviated calendar for the month of September (and October, if
necessary):

     Tishri     1               September:   7
          (8)  (9)  10                     (14) (15) 16
          15                                21
          22                                28

     Essentially, all you are doing in either calendar is counting by
sevens from your starting day, the Feast of Trumpets. Atonement is nine
days later in the month, so it might help you to think 1, 8-9-10, 15,
22 and correspondingly for this example, 7, 14-15-16, 21, 28.

     As another illustration for the fall festivals, what happens when
Trumpets is on September 25? Here you must remember to change months,
but that's no horrendous problem!

     Tishri:      1      September :     25
             - - 10                     (32) (33) (34) = Oct. (2) (3)
            15                           39            = Oct.  9
            22                           46            = Oct. 16

     September has 30 days, so you can simply call October 1, September
"31" for calculation purposes. September 46 is simply 16 days after
September 30, or October 16.

     What happens when Trumpets is on August 28? The other fall
Festivals will occur in the month of September. In order not to get
involved with negative numbers, go ahead and add seven days, which is
equivalent to finding Tishri 8. What day is August 35? September 4,
because August has 31 days. September 1 is the same as August 32;
September 2 the same as August 33, etc.

     Your abbreviated calendar will appear:

     Tishri     1                       August    28
               (8)  (9)  10             Sept.     (4)  (5)  6
               15                                 11
               22                                 18

     Observe that you are making a direct correspondence between the
Hebrew calendar and the Roman calendar. Counting by full weeks -- "by
sevens" -- enables you to avoid other computational confusions that can
creep into your work if you just add days. You can add 9 days to the
Roman date of Tishri 1 and find the date for Atonement; 14 days to
Trumpets for the first day of Tabernacles, and 21 days for the Last
Great Day. Counting by sevens with an abbreviated calendar is less
error-prone, once you understand the principle.

     Here are a few problems for you to practice determining the Roman
dates for the annual Festivals. Just indicate the dates for Atonement,
the first day of Tabernacles, and the Last Great Day, but include the
day of the week.

8.5   Trumpets is September 5, Monday
8.6   Trumpets is September 12, Thursday
8.7   Trumpets is September 23, Tuesday
8.8   Trumpets is August 25, Tuesday
8.9   Trumpets is September 16, Thursday
8.10  Trumpets is August 26, Sabbath

The problems are worked for you on the next page.

8.5  September  '5'        Monday     (Feast of Trumpets)
                12 - '14'  Wednesday  Atonement, September 14
               '19'        Monday     Tabernacles, Sept, 19 (first day)
               '26'        Monday     Last Great Day, Sept. 26

The single quotation mark dates are the answers, following the same
format as above:

8.6  September '12'           Thursday       (Trumpets)
                19 - '21'     Sabbath        Atonement
               '26'           Thursday       First day of Tabernacles
               '33' (Oct. 3)  Thursday       Last Great Day
 

8.7  September '23'                          Tuesday
                30 - '2'      October 2      Thursday
                '7'           October 7      Tuesday
               '14'           October 14     Tuesday
 

8.8  August '25'                                  Tuesday
             32  - '34', or September  1  -  '3'  Thursday
                                      '8'         Tuesday
                                     '15'         Tuesday

8.9  September '16'                          Thursday
                23 - '25'                    Sabbath
               '30'                          Thursday
               '37' which is October '7'     Thursday
 

8.10 August   '26'                           Sabbath
               33 - 34, or September 2 - '4' Monday
                                    '9'      Sabbath
                                   '16'      Sabbath

     Take a look at the spring season. Once you find the date for
Passover (which you'll learn how to do very shortly), all you need to
do is find the equivalent dates for Nisan 15 and Nisan 21. An
abbreviated calendar for Nisan looks like this:

               Nisan     14   15
                         21

     If Passover were April 18, you would have:  April 18   19
                                                       25

     The procedure is the same as for the fall season. Just remember
that March has 31 days, so March 32 is the same as April 1. (You
handled the 31 days in August the same way.)

     Now indicate the Roman dates and day of the week for the first day
of Unleavened Bread and the last day of Unleavened Bread in the
following problems:

8.11 Passover is April 10, Monday
8.12 Passover is March 25, Friday                 The problems are
8.13 Passover is March 29, Friday                 worked for yo on
8.14 Passover is March 23, Wednesday              the next page.
 
 

8.11 Passover is April  10  '11'   Monday    Tuesday
                       '17'        Monday

     To be sure you understand the pattern of this answer,
          Passover is Monday, April 10
          1st day of Unleavened Bread is Tuesday, April 11
          7th day of Unleavened Bread is Monday, April 17

8.12 Passover is March 25  '26'                   Friday    Sabbath
                           '32' which is APRIL 1  Friday
 

8.13 Passover is March 29  '30'                   Friday    Sabbath
                      '36'      which is APRIL 5  Friday
 

8.14 Passover is March 23  '24'              Wednesday Thursday
                      '30'                   Wednesday
 

     Now turn your attention to finding the date of Passover, once you
know the Roman date for Trumpets. As you learned earlier in this
program, Passover is 164 days before the Feast of Trumpets. What you do
is count by whole Roman months until you obtain a number slightly
larger than 164. (You can also find a number of days below 164.)

     An example will clarify the procedure. Suppose Trumpets is on
September 13. You want a number bigger than 164 days, so you mentally
keep track of the months you are adding:

                         September:       13 days
                         August:          31 days
                         July:            31 days
                         June:            30 days
                         May:             31 days
                         April:           30 days
                         --------------------------------
                                         166 days

     166 days brings you to the last day of March. How many days past
164 did you go? 166  -  164  =  2. Two days into April is April 2 --
Passover.

     Doing this the other way, had you only counted as far as May, you
would have come up with 136 days. 136 days brings you to April 30. How
many days into April must you go? 164  -  136  =  28 days. April 30
minus 28 days is April 2 -- Passover.

     Take another illustration, Trumpets being on August 30. You have:

                         August:          30 days
                         July:            31 days
                         June:            30 days
                         May:             31 days
                         April:           30 days
                         March:           31 days
                         --------------------------
                                         183 days

     183 days takes you to the last day of February, How many days into
March is Passover? 183 - 164 = 19 days. Passover is March 19.

     Once you practice on a few problems, you will have no difficulty
in determining the Roman date for Passover. In these problems, also
indicate the day of the week:

8.15 Trumpets is September 8, Thursday
8.16 Trumpets is September 11, Sabbath
8.17 Trumpets is September 5, Monday
8.18 Trumpets is August 25, Sabbath

The answers are listed for you below.

8.15 Passover is March 28, Monday
8.16 Passover is March 31, Wednesday
8.17 Passover is March 25, Friday
8.18 Passover is March 14, Wednesday

     You've now learned how to find the day of the week and the Roman
day of the month for all the Holy Days except Pentecost. Of course, you
already know the day of the week. But how about the Roman date?

     Before you can count fifty days to Pentecost, you need the
starting point, which is the Sunday of the wavesheaf offering. The
table below will give you an overview of the relationship of Passover
and the wavesheaf offering:
                                                       Days after
          Passover (Nisan 14)      Wavesheaf offering  Passover
          ========================================================
          Friday (Thurs. eve)      Nisan 16 (Sunday)        2
          Wednesday                Nisan 18                 4
          Monday                   Nisan 20                 6
          Sabbath                  Nisan 15                 1
 

     There's really no need to memorize this table, because you can
easily determine the number of days from the Passover to the wavesheaf
offering once you find the day of the week Passover occurs. Just count
from the Passover to the Sunday of the wavesheaf offering.

     When the Passover is on Monday, March 28, the Sunday of the
wavesheaf offering is 6 days later, March 34 = April 3. With April 3 as
the first day (counting inclusively), Pentecost, the fiftieth day, will
be 49 days later. There are 30 -  3 days left in April, or 27 days.
Pentecost is 49 - 27 days into May, or on May 22. As another way for
determining the date of Pentecost, count seven full weeks from April 3.
Here you are counting by sevens: April 10, 17, 24, May 1, 8, 15, 22.
Again you have arrived at May 22 for the date of Pentecost.

     Here's another example for determining the date of Pentecost. If
Passover is on April 8, a Wednesday, the wavesheaf offering will be
April 12, Sunday. Count seven full weeks from April 12: 19, 26, May 3,
10, 17, 24, 31. Pentecost is May 31.

     Work out a few problems in order to firm up the process in your
mind. Determine Pentecost for each of the following cases

8.19 Passover is Friday, March 30
8.20 Passover is Wednesday, March 16
8.21 Passover is Sabbath, April 2
8.22 Passover is Monday, April 20

                    The answers are on the next page.

8.19 Pentecost is Sunday, May 20

8.20 Pentecost is Sunday, May 8

8.21 Pentecost is Sunday, May 22

8.22 Pentecost is Sunday, June 14

     You have learned how to work with the Holy Days in separate steps,
fall festivals, Passover and Pentecost. Now integrate those skills and
find for all the Holy Days in a Roman year the respective date and day
of the week.

8.23 Trumpets is Monday, September 16

8.24 Trumpets is Sabbath, October 3

8.25 As the last problem in this series of programs, determine the day
          of the week and the Roman date for all the annual festivals
          in the year 2055 AD. You may use the chart included in
          Program 4.

The answers are below.

8.23      Passover                      Friday, April 5
          1st day of Unleavened Bread   Sabbath, April 6
          7th day of Unleavened Bread   Friday, April 12
          Pentecost                     Sunday, May 26
          (Trumpets                     Monday, September 16)
          Atonement                     Wednesday, September 25
          1st day of Tabernacles        Monday, September 30
          Last Great Day                Monday, October 7

8.24      Passover                      Wednesday, April 22
          1st day of Unleavened Bread   Thursday, April 23
          7th day of Unleavened Bread   Wednesday, April 29
          Pentecost                     Sunday, June 14
          (Trumpets                     Sabbath, October 3)
          Atonement                     Monday, October 12
          1st day of Tabernacles        Sabbath, October 17
          Last Great Day                Sabbath, October 24

8.25  See Program 5, pages 44 and 45 for the determination of Tishri 1

          Passover                      Monday, April 12
          1st day of Unleavened Bread   Tuesday, April 13
          7th day of Unleavened Bread   Monday, April 19
          Pentecost                     Sunday, June 6
          Trumpets                      Thursday, September 23
          Atonement                     Sabbath, October 2
          1st day of Tabernacles        Thursday, October 7
          Last Great Day                Thursday, October 14
 
 
 

                        ----------###----------

                         SAMPLE TEST QUESTIONS

1.   How many lunar months are in a 19-year cycle?

2.   How many 19-year cycles, leap years, and common years are between
          the bench mark and 171 AD?

3.   Without using your chart, determine the REDUCED number of days,
          hours, and parts in TWO common Hebrew years.

4.   Demonstrate (or derive) without charts the amount that the Hebrew
          common year leads or trails the Roman calendar.

5.   What corrections (Roman leap year and Julian / Gregorian) are
          applicable for the following years:

          971 BC    1716 AD   1291 AD   1900 AD   2155 AD

6.   In 1984 AD the molad Tishri is September 25, Tuesday 11 h 976 p.
          What is the day of the week and the day of the month for
          Trumpets?

7.   If the 29th of Elul is a Wednesday, what day of the week is the
          15th of Elul?

8.   What day of the week is 313 days before a Friday?

9.   In 1981 AD Trumpets is on September 28, Monday. List the day of
          the week and the day of the Roman  month for each of the
          annual festivals given in Leviticus 23.

10.  List the day of the week and the day of the Roman month for all
the annual festivals in the year 29 AD. You may use your chart.

                            HEBREW CALENDAR

     Name of Month*      #Sacred   #Civil    Begins with new moon of
     --------------      -------   ------    -----------------------
     Aviv, or Nisan      1st         7th          March-April

     Ziw                 2nd         8th          April-May

     Siwan               3rd         9th          May-June

     Tammuz              4th        10th          June-July

     Av                  5th        11th          July-August

     Elul                6th        12th          August-September

     Tishri, or Ethanim  7th         1st          September-October

     Marcheshwan         8th         2nd          October-November

     Kislew              9th         3rd          November -December

     Teveth             10th         4th          December-January

     Shevat             11th         5th          January-February

     Adar               12th         6th          February-March

     (*) Modern Hebrew transliteration. Please compare with that below:

     The spelling given in W. M. Feldman's, "Rabbinical Mathematics and
Astronomy," is as follows:

                    Nisan          Tishri
                    Iyar           Marcheshvan
                    Sivan          Kislev
                    Tammuz         Tebeth
                    Ab             Sh'bat
                    Elul           Adar
                                   V'Adar

     Use this as a guide for pronunciation.
 

                    THE SIX TYPES OF HEBREW YEARS

                         COMMON                        LEAP

Month     Deficient  Regular  Perfect   Deficient  Regular  Perfect

Tishri        30        30      30          30        30       30

Marcheshwan
 (Heshwan)    29        29      30          29        29       30

Kislew        29        30      30          29        30       30

Teveth        29        29      29          29        29       29

Shevat        30        30      30          30        30       30

Adar          29        29      29          30        30       30

V'Adar        __        __      __          29        29       29

Nisan (Aviv)  30        30      30          30        30       30

Ziw (Iyar)    29        29      29          29        29       29

Siwan         30        30      30          30        30       30

Tammuz        29        29      29          29        29       29

Av            30        30      30          30        30       30

Elul          29        29      29          29        29       29
            -----------------------       -------------------------
             353       354     355         383       384      385
            =======================       =========================

(*) Modern Hebrew transliteration. See the top of this page for
alternate spelling and pronunciation.