Just out of curiosity, I calculated that the calendar cycle of of 19 years with 235 lunar months is about two hours too long, which means a day gets added every 12 cycles or 228 years. Unless corrected, this means it is now running about 10 or 11 days later than it was in biblical times and would result in Rosh Hashona being in mid-winter in a few thousand years. Is there any thought to correcting it? I guess the only way would be to have a cycle with only 234 months.
You are correct with regard to your observation that the calendar is a number of days further ahead than it was when it was first established about 1700 years ago.
There has been no serious thought given to correct it. It will probably not be given serious thought until Passover begins to get pushed into the summer a few thousand years from now. Of course, we hope by then that the Messiah will have arrived and the matter will be corrected by itself.
Zev Steinhardt
There is probably some rule regarding the one-or-two-day Rosh Chodesh of Heshvan and/or Kislev that corrects for it. But it might not show up if one simply takes a standard 19-year cycle and multiplies it x number of times.
Sorry, but as long you stick to a lunar calendar, the only possible correction is to delete a month at some point. That 19 year cycle is an astronomic cycle and you cannot correct by starting a month a day earlier. Zev has given the answer I more or less expected, but I was curious whether any thought has been given to it.
Since there already is an intercalary month, Adar I, added 7 times in 19 years, it would seem the obvious correction, if one was desired would simply be to skip Adar I one time.
And I never did understand why it was decided to slip the intercalary month before Adar and call it Adar I and rename Adar to Adar II in those years. It would simply seem to add confusion (and frustration to any little kid whose birthday was in Adar and had to wait an extra months for it in those years? – Is that an issue at all, do the very religious Jews celebrate birthdays or bar mitzvahs by the the Jewish calendar?
Bat/Bar mitzvas are certainly celebrated according to the Jewish calendar. If you were born in Adar I or II, but there’s only one Adar in the year you turn 12/13, your birthday is during that Adar either way. This means that if Jacob was born on 30 Adar I, and Daniel was born on 10 Adar II, Daniel’s birthday/bar mitzva would come first in a non-leap-year, even though he’s been alive for fewer days than Jacob has. Would it be better if we called the intercalated month something unrelated, and kids born in that month didn’t reach legal majority until 13 leap years had passed? (ie, until they’re in their early 30’s?)
That wasn’t actually my question. My question is why is it specifically the intercalay month that is Adar I rather than the Adar that comes every year being Adar I. I’m not sure it matters really.
Hari Seldon:
The Jewish calendar has some built-in adjustments (which is what I was talking about) that are based not on astronomy but on the need to have the first day of Rosh Hashana fall on a Monday, Tuesday, Thursday or Saturday. See the section “Rosh Hashana postponement rules” in this Wikipedia page. Check out if your “pure” calendar at any point causes Rosh Hashana to begin on a Friday, Sunday or Wednesday. If so, then the adjustments made for this purpose probably balance out the discrepancy that you noted.
I was going to refer to the postponement rules also. I would expect that those rules can be tweaked to keep the calendar from drifting too much, lest Pesach and Sukkot not start on schedule (first full moon after the equinoxes).
To “tweak” them to go back to the calendar of 1700 years ago would require starting Rosh Chodesh 8 days before astronomical new moon. Delays of one day, occasionally two, to prevent certain fasts or feasts from being on Fridays or Sundays are just temporary adjustments, not permanent changes and cannot possibly be used for real change to the calendar. On the other hand, a whole month adjustment (evidently having only 6 leap years in one cycle) would come only once every 7000 years or so. A better scheme would to simply decree that Rosh Hashonah cannot start later than the equinox and nor earlier than one month before it and add leap months as needed.
A similar situation forms a plot point in Gilbert and Sullivan’s “The Pirates of Penzance” play, though based around the Gregorian calendar rather than the Jewish one.
The protagonist’s apprenticeship contract states that he is bound as an apprentice (unfree labor) until his 21st “birthday”, and he was born on February 29th on a leap year, so his 21st “birthday” won’t come until he is 84 years old.
Sorry, this is an old thread but I was searching to see if anyone had started a Rosh Hashanah thread and came across this question.
The answer is that Purim (which is in Adar) has to be 30 days before Pesach (which is in Nisan, the next month). You don’t celebrate Purim twice on leap years*, so it has to be in the month closest to Nisan - Adar II. Therefore, Adar I is the extraneous month because it doesn’t matter if it’s longer between, I don’t know, Tu b’Shevat and Purim.
You may ask why it’s so important that Purim come 30 days before Pesach, and the answer is that I don’t know, but making up connections between them is really good sermon fodder.
*except for Purim Katan, a hilariously useless holiday that is supposed to be celebrated in exactly the same way as Purim, except for all the things you do on Purim, which you don’t do on Purim Katan. With me? Good, me neither.