Question: Daf includes the halacha of saying "shayloh" in the galus from sixty days after the Tekufa. The Tekufa refered to is the autumnal equinox which is Sept 21/22. Sixty days after that is Nov 20/21. Why then do you begin only on Dec 5/6 in the galus? The Artscroll ( Hebrew ) claims that this difference is due to the difference between the Gregorian and Julian calendars and we (halachically) still use the Julian calendar. This makes no sense since the Julian calendar date for the equinox is even earlier than Sept 21/22.
The date of December 4/5 (or 5/6, depending on whether you refer to it as "the night of December 4th" or "the night going into December 5th," as we wrote in a previous discussion) is based on the equinox being September 23. Sixty days after the Tekufah used to be in November, as you wrote, until the date was changed in the year 1582 CE when the Gregorian calendar was instituted, as we wrote in the Insights.
Regarding your question that the equinox, according to the Julian calendar which we Halachically still use, is even earlier than September 23, the case is actually the opposite. The Gregorian calendar omitted days from the year in order to rectify the unnecessary addition of days that the Julian calendar was making to the year. Hence, according to the old calendar, the date of the Tekufah was becoming later , and not earlier! Thus, our date of December 4 actually falls out a bit earlier than sixty days after the Tekufah according to the Julian calendar.
This leads to your next question (as related to me by Reb Uri Sondhelm) -- why didn't the Chachamim establish the Halachic calendar based on the date of the actual Tekufah (that is, why didn't the Chachamim adapt the Gregorian calendar with regard to the Halachic matters which pertain to the solar year)?
It seems that since the date of the Tekufah according to Shmuel's calendar (which is basically the same as the Julian calendar) moves off by only a few days every few hundred years, it will only move off by a few weeks by the time that Mashiach comes. Therefore, the Chachamim did not see that as reason enough to change from the date of the Tekufah according to Shmuel's calendar.
Thank you for your response. I have since seen an answer in the Artscroll Birchas Hachama as to why Chazal saw fit to accept Shmuel's tekufa in this case when they clearly knew it to be wrong. For example they didn't accept Shmuel's calculation of the tekufa with regard to Pesach. They did assure consonance between Pesach and tekufat aviv. The answer given is the differentiation between mitzot tzibbur (Pesach) and mitzva pratit (prayer for rain).
I don't think we need continue the relatively arcane discussion on the Julian and Gregorian calendars, but I think one of your statements is incorrect.
"The Gregorian calendar omitted days from the year
in order to rectify the unnecessary addition of days that the Julian
calendar was making to the year. Hence, according to the old calendar, the date of the Tekufah was becoming later, and not earlier! Thus, our date of December 4 actually falls out a bit earlier than sixty days after the Tekufah according to the Julian calendar."
The Julian calendar did in fact add too many days, thus any given Julian calendar date would over the years become later than the "real" solar date. Hence Sept 21 which once was the date of the Tekufa came out centuries later ten days AFTER the Tekufa. As you point out in 1582 when the Gregorian calendar was instituted ten days were dropped- Oct 4 was followed by Oct 15. In that year for example, by the Julian calendar the Tekufa was on Sept 11 and if nothing had been changed Tekufat Teves would have been Dec 11. By dropping 10 days what would have been called Dec 11 was called Dec 21. Thus the following year Tekufat Tishrei instead of falling on Sept 11 fell on Sept 21.
(a) I suspect that the confusion between Charles and yourselves is as follows:
In the old (Julian) calendar they had extra days (for example, Feb 29th in years 1400, 1500, 1700 etc), so what we would say is 1st Mar (in Gregorian) would have been Feb 29th (in Julian). Thus Gregorian 2nd Mar = Julian 1st Mar etc Thus Gregorian 21st Sep = Julian 20th Sep.
According to this, the real astronomical equinox (on 21st Sep Gregorian) would slip BACK a day in every such Julian year (3 years in 400)!
Charles stated that the equinox was getting earlier in the Julian year. This is correct.
The Kollel meant that the Tekufa was defined as 21st Sept. Julian (= 22nd Sep Gregorian etc); when we changed to using the Gregorian, we effectively delayed the Tekufa.
Does this sound plausible?
(b) The Kollel also said:
Thus, our date of December 4 actually falls out a bit earlier than sixty days
after the Tekufah according to the Julian calendar.
Can you clarify this comment also please?
(b) Sorry! It should read, "Thus, our date of November 23 actually falls out a bit earlier...."