Arthur Spier writes:
"Since Biblical times the months and years of the
Jewish calendar have been established by
the cycles of the moon and the sun. The traditional law prescribes that the
months shall follow
closely the course of the moon, from its Molad (birth, conjunction) to the
next New Moon.
Furthermore, the lunar months must always correspond to the seasons of the
year, which are
governed by the sun. The month of Nisan with the Passover Festival, for
instance, must occur
in the Spring and the month of Tishri with the harvest festival of Succoth in
Fall" (p.1).
The Hebrew calendar is a luni-solar calendar, using
both the motions of the moon and the sun to
determine the year. By contrast, the Gregorian calendar is purely solar, and
the Mohammedan
calendar is completely lunar, in which every month follows the moon closely
but wanders through all
four seasons during the period of 33 years.
Since the solar year is about 356 days, and 12 lunar
months are about 11 days shorter than that, the
Jewish calendar has to resolve these two facts and harmonize them. Writes
Spier:
"In the early times of our history the solution was
found by the following practical procedures:
The beginnings of the months were determined by direct observation of the new
moon. Then
those beginnings of the months (Rosh Hodesh) were sanctified and announced by
the
Sanhedrin, the Supreme Court in Jerusalem, after witnesses had testified that
they had seen
the new crescent and after their testimony had been thoroughly examined,
confirmed by
calculation and duly accepted. The Jewish communities were notified of the
beginning of the
months (Rosh Hodesh) in earlier times by kindling of night fires on the
mountains, and later on
by messengers" (ibid.).
A special committee of the Sanhedrin had the mandate
to regulate and balance the solar with the
lunar years. Called the Calendar Council (Sod Haibbur), this council
calculated the beginnings of the
seasons (Tekufoth) "on the basis of astronomical figures which had been handed
down as a tradition
of old." Spier continues:
"Whenever, after two or three years, the annual
excess of 11 days had accumulated to
approximately 30 days, a thirteenth month Adar II was inserted before Nisan in
order to
assure that Nisan and Passover would occur in Spring and not retro- gress
toward winter.
However, the astronomical calculation was not the only basis for intercalation
of a thirteenth
month. The delay of the actual arrival of spring was another decisive factor.
The Talmudic
sources report that the Council inter- calated a year when the barley in the
fields had not yet
ripened, when the fruit on the trees had not grown properly, when the winter
rains had not
stopped, when the roads for Passover pilgrims had not dried up, and when the
young pigeons
had not become fledged. The Council on intercalation considered the
astronomical facts
together with the religious requirements of Passover and the natural
conditions of the country"
(ibid., p.1-2).
This method of observation and intercalation worked
well and was in use throughout the period of
the Second Temple, from 516 B.C. till 70 A.D., and lasted for about another
three centuries after
the destruction of the Temple in 70 A.D., so long as an independent Sanhedrin
functioned. However,
in the fourth century, Roman oppression and massive persecution threatened the
very survival of
Judaism, as well as the continued existence of the Sanhedrin. Therefore, the
Jewish patriarch Hillel II
took an extraordinary step to preserve the unity of Israel. Arthur Spier
writes:
"In order to prevent the Jews scattered all over the
surface of the earth from celebrating their
New Moons, festivals and holi- days at different times, he made PUBLIC the
system of
calendar calculation WHICH UP TO THAT TIME HAD BEEN A CLOSELY GUARDED
SECRET. It had been used in the past only to check the the observations and
testimonies of
witnesses, and to determine the beginnings of the spring season.
"In accordance with this system, Hillel II formally
santified all months in advance, and
intercalated all future leap years until such a time as a new, recognized
Sanhedrin would be
established in Israel. This is the permanent calendar according to which the
New Moons and
Festivals are calculated and celebrated today by the Jews all over the world.
Like the former
system of observa- tion, it is based on the Luni-Solar principle. It also
applies certain rules by
which the astronomical facts are combined with the religious requirements into
an admirable
calendar system" (p.2).
This distinguished authority shows us clearly that
the system of calendar calculation for the Hebrew
calendar did not begin with Hillel II in the fourth century. Rather, it had
been in use among the Jewish
calendar experts since time immemorial. In the years when observation was used
to determine the
calendar, the mathematical/astronomical caculations were used as a "check" on
the witnesses who
testified they saw the new moon's first slender crescent. It was a closely
guarded secret for
thousands of years, known only to the Jewish scribes and priests, rabbis and
spiritual leaders.