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Orthodox Equinox Paradox

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Topic: Dew, Prayer for, Start When?

Lauren Schiff wrote:

My ArtScroll siddur says to add the words 'tal u'matar' [prayer for rain] starting the evening of December 4th. Later I saw in the Book of our Heritage that it says December 5th. Which date is correct?

Dear Lauren Schiff,

The Book of our Heritage is correct.

In Talmudic times, the rainy season in Babylon started 60 days after the autumn 'tekufa' - i.e., the halachic equinox. That's the time of year when the Jews in Babylon started to pray for rain. The Sages fixed this date for all Diaspora Jews.

Whereas all Jewish holidays are based on the moon and don't correlate to the civil calendar, the 'tekufa' is based on the sun. That's why it's the only yearly Jewish occurrence associated with the civil calendar.

The Talmudic sage Shmuel approximated the year to be 365 and 1/4 days long. The 'tekufa' is based on this figure. The Roman calendar established by Emperor Julius Caesar is based on the exact same figure - 365 1/4 days. For a thousand years, everything was rosey.

But in 1582 Pope Gregory XIII changed the calendar to what is now known as the Gregorian calendar, which is the one currently in use. According to this calendar, every fourth year is a leap year except those century years which cannot be divided by 400. For example, the year 1600 was a leap year, but the years 1700, 1800 and 1900 were not. The year 2000 is a leap year.

So the year 1900, which was a leap year according to the Julian calendar, was not a leap year according to the Gregorian. Therefore, the calculations made in the 1800s are no longer valid.

Most current English prayer books today are based on reprinting prayer books from the 1800s; hence, the mistake. Therefore, the words 'V'tein tal u'matar L'vracha' -'Give dew and rain for blessing' - should have been added this year on the fifth of December, and not on the fourth.

Which reminds me of a story of a very punctual Jew. On December 5th he calls his wife and tells her, "I'll be 3 seconds late for dinner tonight, dear, we are starting "Tal U'matar."


  • Tractate Ta'anit 10a
  • Shulchan Aruch Orach Chaim 117:1
  • Iggrot Moshe Orach Chaim 4:17 that the 'tekufa' is according to Shmuel
  • Rabbi Yedidya Menat, author of Luach Kir

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