Preface
The following article titled “Why Is Pesach So Late This Year 1997,” By Saul Leeman, was published in Vol.
25, No.1, 1997 issue of the “Jewish Bible Quarterly.” It is a question and answer format article that attempts to
explain why the Holy Days, as calculated in the Jewish/Hebrew calendar, were one month late in 1997. The Holy
Days will again be one month late in 2005, 2007, 2008, and in 2016. All four of these years, ‘97,’05, and ‘08,
and 16 are considered intercalated 13th month “leap” years. This 13th month is called “Adar II” in the
Jewish/Hebrew calendar and was devised by Hillel II for the convenience of his ‘Postponement Rules’ as
established in that Calendar. I think you will find the following article enlightening, to say the least.
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WHY IS PESACH SO LATE THIS YEAR 1997?
SAUL LEEMAN
Observe the month of aviv and offer a
Passover sacrifice to the Lord your God
Reading this verse in Deuteronomy 16:1 along with the relevant rabbinic literature, one would be justified
in assuming that the Torah intended that the festival should occur, as it most often does, during the first month
of spring season. This year (5757), However, it fails to do so. In order fully to understand the delay in the arrival
of our spring festival, certain questions must be asked:
Why is Pesach so late this year?
Pesach is so late this year (April 22) because this is a leap year in the Jewish calendar with a thirteenth
month is intercalcalated. In every 19-year cycle there are 7 leap years: the 3rd, 6th, 8th, 11th, 14th, 17th, and 19th.
Yes, I know that. But in the course of the past 10 years or so, there have been a number of leap years, and yet
I don’t recall any Pesach being as late as this one.
That is because this is the 19th year of the cycle, a leap year that occurs after only a two-year interval
following the preceding leap year. The same is true (and even more so) regarding the 8th year of the cycle. Thus
there are these two years in every cycle when Pesach is late in the spring. In 1967 (an "8th year") Pesach fell
on April 25, the latest it has been so far. You say, “so far.”
Does that mean that Pesach can be even later than April 25?
Yes, indeed-- and this is the major problem of the Jewish calendar; i.e., that it is based on a calculation
of the solar year that is inaccurate by about 6 ½ minutes. It is this inaccuracy that moves Pesach in the direction
of the summer at the rate of almost a full day every 200 years, amounting to about 4 1/2 days every 1,000 years.
This means that in about 1OOO years hence, Pesach will be celebrated as late as May 1, and 8,000 years hence,
it will be as late as June 1.
Can this be corrected?
This can be corrected only through calendar reform based on a recalculation of the calendar structure.
You say that calendar refrom will eventually be necessary. Has there ever been such a things in recent history?
Yes, there has. In 1582 the Julian calendar, which had been in force since 46 BCE, was replaced by the
Gregorian calendar. The Julian calendar, institued by Julius Ceasar, was based on a calculation that reckoned
the length of the solar year at 365 days and 6 hours, when in reality it is about 11 1/4 minutes shorter.
This difference accumulated to an error of about 3 days every 400 years (or 7 ½ days every 1,000 years).
As a result, by the 16th century, the vernal equinox retrograded to March 11. To restore it to its correct date, Pope
Gregory XIII declared that the day following October 4 would not be October 5 but October 15. By this
declaration, he restored the vernal equinox to March 21, the date at which it was in the year 325 C.E. when the
Council of Nicea (in order to divorce Easter from Pesach) decreed that the formula for setting the date of Easter
would be “the first Sunday after the first full moon on or after the vernal equinox.”
Note that it was his concern for the proper Easter date that motivated the Pope’s calendar reform.
Having eliminated the accumulated error of 10 days, the Gregorian calendar had also to provide that no such
regression year should re-occur. This is accomplished by decreeing that the century years should not be a leap
year except when it is divisible by 400. As a result of this provision, the years 1700, 1800, and 1900--leap years
in the Julian calendar--were not leap years in the Gregorian calendar. The difference between the two is now 13
days. In the year 2100, the difference will be 14 days.
But Jewish religious practice has no connection with the solar calendar. Aren’t all Jewish observances based
on the lunar calendar?
Not exactly. There are two observances that are linked to the solar calendar. One of them is tal umatar, the
prayer for dew and rain. The Talmud calls for the recitation of this prayer to begin 60 days after the autumnal
equinox and to continue until Pesach. The prayerbook, however, fixes tal umatar day on December 5--73 days
after the equinox (September 23). This discrepancy of 13 days is the difference between the Julian and Gregorian
calendars, and this differential continues to grow at the rate of 7 ½ days every 1,000 years.
With tal umatar day moving in the direction of Pesach at the rate of 7 ½ days every 1,000 years, the former
will eventually overtake the latter in about 35,000 years. Long before that, however, the Pesach date will have
to be adjusted, and thus the tal umatar problem too, will find its solution.
In Israel there is much less “alarm” regarding this problem because in the Holy Land the season of tal umatar
starts in the first week of Heshvan and is not directly linded to the solar calendar at all (See Bab. Talmud, Taanit
10a).
You said that there were “two observances” linked to the solar calendar. What is the other one?
The other one is Birkat ha-Hammah--the Blessing of the Sun, a benediction recited on the occasion of the
vernal equinox once every 28 years when, according to traditions, the earth returns to the same position in
relation to the sun that it occupied at the time of Creation. It is always recited on a Wednesday (the day on which
the sun was created). Its most recent recitation was on April 8, 1981; its next occurrence will be on April 8,
2009. That this is astronomically meaningless was particularly impressed upon us when the Blessing of the Sun
took place on April 8, 1953 when we were then “celebrating the vernal equinox and inaugurating the Spring”--on
the 23 of Nisan, eight days after the advent of Pesach!
When the necessary calendar reform is accomplished, Birkat ha-Hammah will also fall into place. The
“reform” will surely provide that Pesach will always fall on the first full moon of spring (not the second full
moon as is the case this year) and Birkat ha-Hammah will be fixed to occur on the first Wednesday of Spring.
When was our present Jewish calendar instituted and by whom?
The Jewish calendar, as we have it today, was instituted by the Patriarch Hillel II, circa 359 C.E.
Why is it based on a 19-year cycle?
Because the basic formula of the Jewish calendar is following 19 solar years==235 lunar months (19 ordinary
lunar years+7 additional lunar months). The Greeks called this the Metonic Cycle.
Does this mean that every 19 years the civil date (Gregorian) and the “Jewish date” concide?
Yes, every 19 years they either coincide exactly or deviate by one day.
How many days are there in the Jewish calendar?
It varies. In an ordinary year (non-leap year) there are 353 days (defective), 354 days (regular), or 355
(excessive). Similarly in a leap year there are 383, 384, or 385 days.
What is the reason for this?
The reason is a religious one. The basic [lo ‘adu rosh] is that Rosh Hashanah must not fall on a Sunday,
Wednesday, or Friday. If Rosh Hashanah fell on a Wednesday or Friday, Yom Kippur would precede or follow
the Sabbath, resulting in a situation that would involve hardship in its observance. If Rosh Hashanah fell on a
Sunday, Hoshanah Rabbah would fall on the Sabbath and would call for the elimination of certain rituals which
the pharisaic rabbis did not want to forgo. Therefore a built-in flexibility was necessary whereby, if Rosh
Hashanah were to fall on any of these three days, it would be postponed to the following day.
Thus, in a regular year (354 days), the months alternate between 30 and 29 days. In a defective year (353
days), the months of Heshvan and Kislev each has 29 days. In an excessive year (355 days), Heshvan and Kislev
each have 30 days.
What was the procedure before the Patriarch Hillel II instituted the present fixed Jewish calendar?
Before that date, we had an unfixed “living” calendar. The new moon was determined by observation.
Witnesses would come to Jerusalem to testify that they had seen it. If, after interrogation, the Beth Din was
convinced of the validity of their testimony, the New Moon was sanctified, and Rosh Hodesh was declared. The
Beth Din sat in readiness to receive witnesses only on “day number 30" of the outgoing month to determine
whether that very day should be declared as “day number one” of the incoming month. If such a determination
was not made on that day, the next day automatically (with or without witnesses) became Rosh Hodesh, because
the month consists of not less than 29 nor more than 30 days. (See Mishnah Rosh Hashanah, Chapters 1-2).
Once the New Moon was sanctified, the news was then proclaimed throughout the length and breadth of the Holy
Land.
What about the Jews outside of the Holy Land? How was the message transmitted to them?
That is a good question. Often, due to the difficulties of communication, the message did not arrive on time, and
this thrust the Jews outside of Palestine into a serious religious quandary. For instance, when it came to observe
Pesach, they had to speculate whether the previous month consisted of 29 or 30 days. If 29, then Pesach would
be on a certain date; if 30, Pesach would be on the following day. What to do? To resolve the dilemma, they
determined to “play it safe” and to observe the Yom Tov on both days. The same is true of Shavuoth and
Sukkoth. Therefore, we Diaspora Jews (with the exception of our Reform brethren) have five more yom tov days
per year than do the Jews of Israel.
What about Rosh Hashanah?
Rosh Hashanah is observed for two days in Israel also.
So much for the New Moon procedure before the calendar was fixed. Now, tell me how were leap years
determined before the fixed calendar?
Here, too, it was a living situation where the rabbis would deliberate before declaring the month of Nisan to
consider whether or not the signs of spring have arrived (end of rainy season, ripening of grain, equinoctial
considerations, etc.). If the spring seemed to be delayed, then a Second Adar was intercalated and the year
became a leap year (See Bab. Talmud Sanhedrin 11 a & b).
Why was it found necessary to introduce the fixed calendar?
Because the patriarchate in the Holy Land no longer enjoyed its position of primacy and because the Roman
government restricted the freedom of the Sanhedrin to act in these matters.
The Jewish calendar doesn’t seem to be either lunar or solar. What would you call it?
It is a luni-solar calendar, the months being reckoned according to the moon and the year according to the sun.
You have already indicated that its calculation of the solar year deviates by about 6 ½ minutes from the true
astronomical year. What about its calculation of the lunar month?
Here it is as accurate as it can possibly be. The Jewish calendar calculates the month at 29 days, 12 hours, 44
minutes, and 3.33 seconds--a deviation from the true astronomical month of less than one half of a second.
To return now to what you have characterized as the “major problem” of the Jewish calendar--how long will
it take before Pesach occurs on June 21 and will, therefore, no longer be in the spring?
bout 12,500 years.
Isn’t it, then, too early now to worry about calendar reform?
Well, it certainly is not too early to think about it.
How will this calendar reform be carried out ?
There are two ways: One a natural one, the other a supernatural. In one case, there would be a worldwide synod
representing all factions of Jewry that would arrive at an agreement as to how and when to revise the calendar.
In the other case, Elijah will come and settle the matter for us.
I note that you do not specify which of the alternatives you consider to be the natural and which the supernatural.
But, in your view, which of the two eventualities is more likely to occur?
We’ll just have to wait and see.
Vo.25. No.1, 1997 JEWISH BIBLE QUARTERLY
A quote from the “Comprehensive Hebrew Calendar” by Arthur Spier, 1960 Edition, page 227.
“It is evident that the advance of Nisan toward May, at a rate of 4 days in a thousand year, has postponed
Pesach already in the 8th and 19th year of the cycle more than a month from the astronomical spring equinox.
The Tekufoth of Samuel, which are based on the length of 365 1/4 days for the solar years, deviate
considerably from the true astronomical time. They are 17 days later than the astronomical equinoxes and
solstices in our century, a difference which grows by 1 day almost every 100 years.
The rebirth of the state of Israel rekindles in us the hope that a new Sanhedrin, recognize by the whole
people of Israel, will be established again in our time. It will be the task of the Sanhedrin to make a decision
as to when and how the sanctified calendar of Hillel II is to be modified in accordance with the requirements
of astronomy and the Torah.”