I Triple Adar you!

by Michael S. Kaplan, published on 2010/10/22 07:01 -04:00, original URI: http://blogs.msdn.com/b/michkap/archive/2010/10/22/10079237.aspx


Some may consider this blog to be a continuation of I Adar you! Hell, I Double Adar you!, written about 2.5 years prior.

The title might help that opinion, since it is certainly suggests a continuation. :-)

But i'm not sure whether I think of it that way.

The quote I am going to take out of it will also probably help there:

...but the Hebrew calendar starts jumping too far ahead if left to its own devices, so seven out every nineteen years an extra month is added -- generally this is known as intercalation.

You can see how I buried a very technical piece of information about the calendar there in the language.

It looks like the same kind of over-generalization as phrases like "every four years we add a day" in discussing leap years, since that says nothing of the exceptions to the rule.

Unrelated tangential point: We have no other calendar supported by any Microsoft platform that has more than 12 months. I mention this only because someone was asking; also, we have no support for weeks longer than seven days.... :-)

Thinking about the original inspiration behind the Gregorian calendar, mentioned in It's still not a Freedom Tree -- and it's AD, fercryingoutloud!:

...this was for the Gregorian calendar, that so many "Protestant" and well basically non-Catholic countries did not pick up until as long as two centuries later since its secular benefit over the Julian calendar (fixing the drift caused by the Julian year being a tad too long) was ignored due to the specific religious benefit (keeping the date of Easter from drifting further and further).

The driving force behind the Hebrew calendar has a similar motivation, since there are two central guding principles:

  1. Months are strictly lunar, and
  2. Passover must always happen in spring-time.

Now obviously Spring is something driven by the Solar year and it has nothing to do with the moon. So you can think of the calendar as a rather fancy way to keep these two very different cycles (lunar and solar) from falling too far out of sync to mess with some of the expectations around Passover.

The leap months happen in specific years:

years of the full Metonic cycle (it is kind of fun that two of noteworthy uses for the Metonic cycle are in both the calculation of the Hebrew calendar and the calculation of Easter -- though in very different ways!).

Bonus trivia question for the reader: Using just the information here in this blog and no other source, can you explain why one cannot simply say that the Hebrew year's connection to the Gregorian year repeats every 19 years? All of the information you need to answer the question is in this blog and no links need to be followed.

But now that I pointed out the huge effort to correct drift in the Gregorian case, I have to mention another point: the deal with the full day the Hebrew calendar loses every 231 years, as described in Wikipedia here):

"Rectifying" the Hebrew calendar
Given the importance in Jewish ritual of establishing the accurate timing of monthly and annual times, some futurist writers and researchers have considered whether a "corrected" system of establishing the Hebrew date is required, due to the small but accelerating changes in the actual lunar cycle interval. Further religious questions include how such a system might be implemented and administered throughout the diverse aspects of the world Jewish community.

Irv Bromberg has proposed a 353-year cycle of 4366 months, which would include 130 leap months, along with use of a progressively shorter molad interval, which would keep an amended fixed arithmetic Hebrew calendar from drifting for more than 7 millennia.

It has been argued by some that, as the fixed arithmetic Hebrew calendar was established on the authority of Hillel II, President of the Sanhedrin in Hebrew year 4119 (358 CE), only an equal authority (a modern Sanhedrin) can either amend it or reinstate the observational Hebrew calendar. The attribution of the modern Hebrew calendar solely to Hillel II has, however, been questioned, as the rules developed over a long period of time. (see Hillel II)

Microsoft will likely let the problem be solved by others and will just pick up the solution on their own. :-)

The argument that a rabbi of specific stature would be needed is no more odd than those who argue against "modern" solutions in other cases like I mention in Good things can happen when religious authorities work with science and technology:

The real problem (in my opinion) is that the original intent is not completely known. Even if the motivation for rules was known and the rules were made since they were the best at the time, then at this point there is still no way to know if those who made the rules would accept such an innovation or not. Thus it could be easily considered either pious or heretical, depending on how you look at it. And one would be hard pressed to argue the point either way, since it is a legitmate religious question.

My personal take is that from what we know of Hillel, he was a stand-up guy. He's take the correction gracefully and incorporate it. There would even be some parable in there, to boot!

Though the lack of agreement on future course and the lack of desire to splinter Hebrew calendar usage may keep this correction from happening any time soon. Perhaps only when Passover is about to be no longer in the Spring will action finally take place....


Mihai on 22 Oct 2010 10:10 AM:

Trivia: did you know that GetLocaleInfo/GetLocaleInfoEx never returns anything for LOCALE_SMONTHNAME13? (and in general any LOCALE_S*MONTHNAME13)

Michael S. Kaplan on 22 Oct 2010 10:12 AM:

That is the subject of an upcoming blog, actually. :-)

carlos on 23 Oct 2010 7:41 AM:

"can you explain why one cannot simply say that the Hebrew year's connection to the Gregorian year repeats every 19 years?"

The Gregorian calendar repeats every 400 years.  400 is not divisible by 19.  QED.

Simon Montagu on 24 Oct 2010 2:41 AM:

<i>Using just the information here in this blog and no other source, can you explain why one cannot simply say that the Hebrew year's connection to the Gregorian year repeats every 19 years?</i>

Because 19 and 400 do not have a common factor?

Though actually, as I'm sure you know, it's more complicated than that, because the Hebrew calendar doesn't repeat exactly after 19 years anyway because of the days that are added to Marheshvan or subtracted from Kislev in some years.

<i>...from what we know of Hillel, he was a stand-up guy<i>

LOL! I hate to spoil it by pointing out that this is a different Hillel.

John Cowan on 28 Oct 2010 9:48 AM:

The school of Shammai says, The calendar cannot be fixed until the length of the lunar month changes by at least a day.  The school of Hillel says, The calendar cannot be changed until the coming of Hillel IV.  R. Harlan Ellison said in the name of R. Avram Davidson, The calendar is *meshugge* and makes me *farklempt*, but so do the Jews.  The Goy said, That's what I love about both of them.


referenced by

2010/10/26 Note to the NLS API: It ain't ever gonna by 13 o'clock, either.

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