# How often does chanukah start before v'tain tal?

Outside of Israel, we start saying "v'tain tal oomatar livrachah" ("and provide dew and rain for a blessing") in the amida on the evening of December 4th or 5th (depending on the year). Chanukah starts the evening of the 25th of Kislaiv. How often does Chanukah start before we switch to "v'tain tal oomatar livrachah"?

• It feels off topic. I just can't pinpoint why Nov 28, 2013 at 17:44
• The more interesting question is how often chanukkah ends before we start asking for rain in the diaspora. Nov 28, 2013 at 23:07
• Approximately 5 times in the 19 year cycle, the year after when you have two 12 month years in row, or if you prefer year 3, 6, 11, 14 and 17 in the cycle. Remember the first night of Chanukah might be 3rd December but Shabbat, it might be that we don't start V'Tein Tal Umatar until the night of 5th December that year or even 6th (last happened 2003 but that year Chanukah was still later) Jan 27, 2015 at 16:39

I have a book here that lists the Hebrew-calendar dates for starting "v'sen tal umatar" for the years 5750 through 5851. Counting, I see that in 26 of those 102 years (25%) Chanuka starts before that date. (And in two of the years they start the same night: 5787 and 5833.)

• In 5660, 5736 (and then 5907 etc.) rain wasn't requested on chanukkah at all Dec 6, 2018 at 1:23

There can't be a constant ratio for this, as the date of starting v'sein tal umatter changes (on the english calendar) every 3 out of 4 centuries (thus if you look in the Tur you will find a different date than the one in the shulchan aruch, which are both different from what we do). This is because we follow two different opinions in Maseches Rosh Hashana for how to calculate the exact length of a year, and v'sein tal umattar follows the "less exact" calculation. Theoretically, in a few thousand years v'sein tal will start very late and never be before chanuka.

• But there can be a ratio for each set of 100/200 years of "constant" dates. Perhaps someone can provide a complete table until the century where the ration is zero. Jan 16, 2014 at 4:56
• @Double AA The question was how often, not how many times. I was pointing out that "how often" has no answer. There would be a how often for "how often Rosh Chodesh falls on Shabbos" or something which occurs with regular frequency, or how many times Pesach starts on Shabbos in the 19 year or 247 year cycles. There is no "how often" for this question though. Jan 16, 2014 at 18:42
• I don't understand your comment. I said "ratio" not "amount". Jan 16, 2014 at 18:44
• I was addressing the question that was asked by the originator of the question. I was pointing out that there is no pattern, as the two halachos are based on different calculations. There is only a coincidental "ratio" was all that I was trying to point out. Jan 16, 2014 at 18:56
• The Hebrew calendar does not follow exactly either the Julian or Gregorian calendar but is somewhere in between. Ve Tain Tal U'Matar follows the Julian calendar Jan 27, 2015 at 16:35