Sunday, September 09, 2007

It's Rosh Hashanah...isn't it?

Here's an interesting little tidbit I stumbled upon recently. Rosh Hashanah this year begins Wednesday night, but the molad - the timing of the new moon - is early Wednesday morning. See, on an otherwise unmolested calendric system the molad would determine the day of Rosh Hashanah as beginning Tuesday night (as then the molad would actually occur on the first day of Rosh Hashanah) but the traditional calendric system has several different reasons for why the date for Rosh Hashanah can be pushed off for a day or two.



They go into it simply here:



Once the date of the Molad Tishrei has been calculated, some additional considerations must be taken into account to determine the actual date of Rosh HaShanah. These considerations may cause the actual date of 1 Tishrei to be postponed from the date of the Molad Tishrei. There are four such postponements:


First, if the time of the Molad Tishrei is later than 18 hours from the beginning of the day, Rosh HaShanah is postponed to the next day. This probably accounts for the fact that the young moon could not have been observed until the next day.


Second, for common years only, if the Molad Tishrei falls on a Tuesday, and is later than 9 hours and 204 halakhim from the start of the day, Rosh HaShanah is postponed to the next day. This rule prevents a situation in which the postponements for the next year would require the year to be 356 days long.


Third, for years following leap years only, if the Molad Tishrei falls on a Monday, and is later than 15 hours and 589 halakhim from the start of the day, Rosh HaShanah is postponed to the next day. This rule prevents a situation that would require the previous year to be only 382 days long.


Finally, if Rosh HaShanah would fall on Sunday, Wednesday, or Friday, it is postponed to the next day. In combination with one of the above postponements, Rosh HaShanah could be postponed by as much as two days. This postponement prevents certain holidays from falling on the Sabbath.



The site also has a neat number crunching program that tells you when each of the above situations affect a given year's schedule and the rescheduled date for Rosh Hashanah.



Anyway, so the first three issues are essentially practical concerns to keep the entire system from going off kilter, but what really interests me is the last means of postponement. See, what it is referring to is the postponement rule of Lo ADU Rosh which is a mnemonic name, aleph, dalet, vuv to indicate that if the molad falls on the first, fourth or sixth day of the week then Rosh Hashanah is to be delayed. But why those days of the week? What's the significance?

So the Talmud says (Rosh Hashanah 20a) that the reason for the Wednesday and Friday rule is so that Yom Kippur doesn't fall out on either side of Shabbos and it's pushed off from Sunday because otherwise Hoshanah Rabbah can fall out on Shabbos (Sukkah 43a). So the Gemaras continue, respectively, explaining that having Shabbos and Yom Kippur after one another is bad either because then the dead may have to wait two days before burial and/or that food will go bad and that if Hoshanah Rabbah falls on Shabbos then people will be unable to perform the classic aravot beating.

Now, I find this really remarkable for a couple of reasons. The first reason is due to the fact that they seemed to think it was alright to mess around with the whole calender - and the dates of all the holidays - for what is essentially ritual convenience! In the pre-calculated system the molad would happen when the molad would happen and you couldn't just change around the dates at will. Yom Kippur no doubt _did_ fall out on Friday and Sunday on a regular basis. And even more than that, to ensure that people far from Jerusalem were observing the correct date for the holiday they kept two days yom tov - and yet here we are messing around with the holy times for convenience! It is really amazing.

Secondly, if the reason Yom Kippur was so moved was so that two days of Shabbos didn't follow one another - what would those Amoraim make of today's three days yom tov/Shabbos in a row?! But besides that, even within the calculated system, Pesach comes up against Shabbos pretty regularly - as it does this year - and Shavuous too regularly does the same. So I'm not even sure I understand their reasoning. Do the dead not have to wait the same two days? In any case, I'd much rather have it set up so that Pesach can never begin on a Saturday night rather than Yom Kippur getting that special concern.

Lastly, I'd like to say a few words about the molad itself. The molad was initially figured out by eye witnesses and was taken very seriously as the Mishnah and Gemara report in great detail. Indeed, witnesses could break the Shabbos to travel to the court to make sure that the molad was set on it's proper time. But as that system became impractical the molad was calculated into a calendric system that could operate independently of witness' sitings. So the molad was calculated to be 29 days 12 hours and 44+1/18 minutes after the previous molad (possibly taken from Ptolemy), which was actually very accurate. But the problem is that due to tidal effects between the Earth and Moon, the mean time for the Moon's orbit is now _less than_ what it was in Hillel II's day. The difference is about 0.6 seconds each month and the accumulated molad has by now gained almost 100 minutes on the actual molad that witnesses would report.

The consequence of this is that today the calculated molads are no longer somewhere between Israel and Babylon as it was during the Talmudic period. Now they are calculating a molad that happens somewhere over Afghanistan! And with a difference of over 100 minutes (out of 1440 minutes in day) that means that the molad is calculated to be on the _wrong day_ about 7% of the time! Link

Now that's some weird stuff, isn't it?

I guess I'll just leave this off with wishing all my readers a shana tovah umetukah and a pleasant Rosh Hashanah....assuming it actually is Rosh Hashanah, of course.

6 comments:

Baal Habos said...

OP,

> In the pre-calculated system the molad would happen when the molad would happen and you couldn't just change around the dates at will. Yom Kippur no doubt _did_ fall out on Friday and Sunday on a regular basis. And even more than that, to ensure that people far from Jerusalem were observing the correct date for the holiday they kept two days yom tov - and yet here we are messing around with the holy times for convenience! It is really amazing.


I think this is understood very simply as follows; I don't see it as a kashia. The months were given over to Beth Din to do as they please, in other words , Lo Bashomayim. It's up to sanhedrin, I.e the judgemt to be Me'aber, etc. I think Bais din also had the right to delay witnesses from testifying abojut the molda so it's possible La Ado Rosh was ALWAYS enforced.


As far as three day Yom Tov is concerned, it's not a stirah either because we are not prevented from COOKING two days in a row, You can cook on Yom Tov,. also I believe the dead are vuried on Yom Tov sheni.

Orthoprax said...

Baal,

It's true that the prerogative to set the start of the year was taken by the beit din, but even so, for any situation, it strikes me as remarkable that the technical holy times are so flexible. There seems like a disconnect between the deep significance given to witnessed reports of the molad and the court's willingness to mess around with assigning the start of the year for reasons that were sometimes just simple convenience.

In any case, I highly doubt that Lo Ado Rosh existed from the start of Judaism. There was a time before the beiti din and there is no sign of an organized calendrical system for ancient times. The molad was definitive - which also explains why roshei chadashim were so much more important back in the day.

Furthermore, the gemara in Rosh Hashanah 20a talks about the Elul postponement as a novel creation as Rabbi Ula is reporting to the rabbis in Babylon.

"As far as three day Yom Tov is concerned, it's not a stirah either because we are not prevented from COOKING two days in a row, You can cook on Yom Tov,."

I guess I wasn't clear. R' Ula in doesn't refer generally to food with reference to cooking, but that herbs would go bad - which would require picking of fresh plantstuffs. That would still be an issue for yom tov - if not for modern conveniences.

"also I believe the dead are vuried on Yom Tov sheni."

That's true. And also in the gemara, the issue of dead bodies is dismissed since they can always hire a goy to bury the dead.

alex said...

"it strikes me as remarkable that the technical holy times are so flexible."

According to the Shem miShmuel, it struck the ancient Greeks as "unpalatable" -->

http://books.google.com/books?id=-fj-sKboVBoC&pg=PA85&lpg=PA85&dq=greeks+rosh+chodesh&source=web&ots=gVWEEv61My&sig=Gbxvp-Ncj_LWigKv_xjPf-RdiHU#PPA85,M1

If that doesn't come in, let me parse it:

http://books.google.com/books?id=-fj-sKboVBoC&pg=
PA85&lpg=PA85&dq=greeks+rosh+chodesh&source=
web&ots=gVWEEv61My&sig=Gbxvp-Ncj_LWigKv_
xjPf-RdiHU#PPA85,M1

Baal Habos said...

> There was a time before the beiti din and there is no sign of an organized calendrical system for ancient times. The molad was definitive - which also explains why roshei chadashim were so much more important back in the day.


Quite intresting. If what you say is true, in antiquity, how did people comply with Issur Mlacha on Rosh Hashana? They had absolutely no notcie? Especially, if Eidim came in the middle of the day? Is that possible? Rosh Chodesh is easy, all they were required to do was a mussaf. But R"H?

Orthoprax said...

Baal,

That's a good question. You would think declaring New Moons would require a central authority for everyone to be on the same page, but there were times (think Judges) when a central authority did not exist.

I presume that there was some common system of counting months that everyone was familiar with and local priest/astronomers made the call and publicized it by blowing horns. Indeed, a similar lunar calendar system of the ancient Babylonians predates Israelite civilization.

I suspect the eidim system came later on and that had some of the problems your refer to - hence Rosh Hashana is observed for two days even within Israel.

Yehudi Hilchati said...

As someone else commented, Lo Bashamayim Hi. What it comes to is that Rabbinical Judaism (and its calendar) is certainly man-made. The question is, or course, completeley man-made or man-made within a context provided by God?