1 part (halek or chalyek) 
= 
76 moments (reaim) 
A part consists of 76 moments. 
1 hour 
= 
1080 parts (halakim or chalakim) 
The hour consists of 1080 parts or
halakim or chalakim. Each halek is equal to 3 1/3
seconds. Use of parts or
halakim has the advantage of eliminating fractions. We will use the
English word parts for simplicity. 
1 day 
= 
24 hours 
Genesis 1:5 shows that a day begins in the
evening. While a new day begins with the setting of the sun, 6 p.m. is the
arbitrary start of a new day e.g., Monday starts on Sunday 6 p.m. This
moment is called Monday 0 h in the Jewish calendar. At John 11:9 Jesus refers to the daytime
consisting of 12 hours. 
1 week 
= 
7 days 

1 mean synodic month 
= 
29 days 12 hours 793 parts 
A lunar month is the time needed for the
moon to revolve around the earth. As this period, called a lunation,
varies from monthtomonth, a mean synodic month of 29 days 12 hours 793 parts, or 44 minutes 3 1/3
seconds, is the traditional
average used for calculation. Actual calendars cannot be based upon 29½
days so the Hebrew Calendar incorporates months of 29 and 30 days. 
start of new year 


The year starts with the moment
of the mean molad (mean conjunction, mean astronomical New Moon) of the
month of Tishri (Frank1956:14). 
1 common year 
= 
12 lunar months 
A common year will have 353,
354, or 355 days. 
1 intercalary year 
= 
13 lunar months 
An intercalary year, also called an
embolismic year or leap year, will have an extra month of 30 days.
Leap years may have 383, 384, or 385 days. 
1 nineteen year cycle 
= 
235 lunar months, or 12 common years
and 7 intercalary years 
Every 19 solar years (of some 365¼
days), the moon has revolved around the earth 235 times. Each lunation being
on the average of 29 days 12 hours 793 parts. This is also known as the
cycle of Meton or Metonic cycle. This astronomical relationship makes it
possible to combine common years and leap years together in a fundamental
pattern which repeats itself every nineteen years. Nevertheless, you should
be aware that 235 lunar months is about an 1½ hours less than 19 Julian
years. To be precise, 235 lunations is 1 hour 485 parts less than 19 Julian
years. 
molad 


The computed time for the conjunction of the
sun, moon, and the earth is a molad, from the Hebrew molad (plural,
moledoth). The word means rejuvenation or renewal. 
Molad Tohu 


The time of the mean molad at the
beginning of its year 1, 2nd day (Monday) 5 hours after the beginning of
Monday (reckoning days in Hebrew time beginning at 6 p.m.), which is Sunday
11 p.m. or 23 h 204 p. Sunday. In Jewish tradition "This moment would fall
almost 12 months before Creation and is, therefore, proleptic, a
chronological fiction....and only its final 5 days and 14 hours were after
creation" (Frank
1956:15). 
The bench mark (the Molad of Tishri)
for the year 3761 BCE 
= 
1 day 23 hours 204 parts
(Sunday, October 6 on the Julian Calendar) 
Tishri is the seventh month on the sacred
calendar and the first month of the civil calendar. The Molad of Tishri is
the computed time of the new moon of the month of Tishri.
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 BCE
(reckoning days in Roman time beginning at midnight), can
serve as bench mark. For ease in calculation the most practical choice for a
bench mark is the Molad of Tishri of year one in a 19year cycle. 
molad advancement 


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. 
Leap Years in the presentday Jewish
Calendar (New Cycle) 
= 
Year 3, 6, 8, 11, 14, 17, and 19 in a
nineteen year cycle 
A difference of 6 minutes 39.371 seconds in the Hebrew
calendar's solar year and the true astronomical value causes Passover to
occur one day later every 216 years. This eventually would place Pentecost
in the beginning of summer. This violates the rule that Pentecost must be in
the spring necessitating a postponement, by
one year, of the intercalary months on or after 257 CE. 
Leap Years in the time of Moses
through the Apostolic Age (Old Cycle) 
= 
Year 2, 5, 7, 10, 13, 16, and 18 in a
nineteen year cycle 
Computer calendar programs which do not take
into account the one year postponement in the leap years provide incorrect
dates. 
Leap Years in the time of the
Patriarchs (Patriarchal Cycle) 
= 
Year 1, 4, 6, 9, 12, 15, and 17 in a
nineteen year cycle 
The rule that Pentecost can only occur in
the spring also requires that a postponement, by one year, of the
intercalary months had to have occurred in patriarchal times. The phenomenon
occurs about every two thousand years. 
elapsed time 


The excess over full weeks from the bench
mark to the molad of the required year. 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. 
SO 
= 
Seder Olam 

AM 
= 
Anno Mundi 




