By Daniel J. Lasker
Daniel J. Lasker is Norbert Blechner Professor of Jewish Values at Ben-Gurion University of the Negev, Beer Sheva, and is chair of the Goldstein-Goren Department of Jewish Thought. His landmark work Jewish Philosophical Polemics against Christianity in the Middle Ages, originally published in 1977, was recently republished with a new introduction in 2007.We Jews in Israel have been praying for rain since the seventh of Marheshvan (the night of Thursday, October 18), but, unfortunately, so far the prayers have generally not yet been answered (especially in Beer Sheva where I live). Next week, it will be the chance of Jews who live in the Diaspora to pray for rain, beginning in Maariv of the night of Wednesday, December 5 (the eve of December 6). As undoubtedly all readers of the Seforim blog know, the dates for asking for rain (adding the words ve-ten tal u-matar li-verakha to the ninth blessing of the Shemoneh Esreh, in the Ashkenazi and Nusah Sefarad rites; or changing the form of that blessing from Barkheinu to Bareikh Aleinu, in what is now usually known as the Edot ha-Mizrah rite) are different for the Land of Israel and for the Diaspora. Perhaps not all readers know 1) why there is a difference; 2) why most years one begins the prayer in Maariv of December 4 (the eve of December 5); and 3) why one begins on December 5 this year.
This is Professor Lasker’s first post at the Seforim blog.
Mishnah Ta’anit 1:3 reads: “On the third of Marheshvan one is to begin praying for rain; Rabban Gamaliel says: ‘On the seventh of that month, fifteen days after the feast of Tabernacles, so that even the tardiest Israelite may reach the Euphrates [on the return journey from the pilgrimage to Jerusalem].’” The Talmud (Ta’anit 10a) records Rabbi Eleazar as stating that the law follows Rabban Gamaliel. Despite the fact that the pilgrimage on Sukkot is no longer binding, and modern methods of transportation obviate the need to wait two weeks for the pilgrims to return home, the practice has remained constant: in the Land of Israel, she’elat geshamim (the prayer for rain) begins on the eve of the seventh of Marheshvan.
The same Talmudic passage records that, in the Golah, the practice was to wait “until the sixtieth [day] of the [autumnal] equinox (ad shishim ba-tequfah)” before beginning the prayer. No explanation is given for this difference between Israel and Babylonia, but there are good reasons to believe that it has to do with the meteorological and agricultural differences between the countries. Jews in Babylonia did not need, nor did they want, the winter rains to begin until two thirds of the autumn season had passed; therefore, they waited longer before beginning the prayer. Both communities, however, began “mentioning” rain (mashiv ha-ruah) on Shemini Atzeret, and they ceased mentioning rain and saying the special prayer for rain at Passover.
What about Jews in other countries? Should Jews in these areas pray for rain according to the needs of their own country of residence, as did Jews in the Land of Israel and in Babylonia, or should they employ an already established schedule? Since Babylonian procedures were usually followed in the whole Diaspora, it became the practice of Jews almost everywhere outside the Land of Israel to offer their prayers for rain on the same dates as did their Babylonian coreligionists.
This generalization did not go unchallenged, and the most noteworthy attempt to alter the practice was made by Rabbeinu Asher ben Yehiel (Rosh, c. 1250-1328). He tried to establish the principle that each Jewish community would pray for rain when they actually needed it in their country; this attempt was rebuffed by his contemporaries. The Rosh’s failure to innovate a change in the practice, no matter how sensible it might have seemed, was a major reason why no one in the northern hemisphere ever again challenged the prevailing practice. Questions did arise, however, when Jews migrated to areas in the southern hemisphere, when the order of the seasons is reversed. Rabbinic opinion has usually held that the Babylonian pattern should be followed even when the local winter occurs during summer in Babylonia and vice versa. The result is that to this day, Jews throughout the Diaspora set their liturgical calendar in this regard according to the agricultural needs of Iraq, a country which is now almost devoid of Jews.
But why December 4? The Talmud says “the sixtieth day of the autumnal equinox,” and the autumnal equinox this year fell on September 23, 2007, at 5:51 AM, on the American eastern seaboard, making the sixtieth day on November 21. The answer to this question is to be found in a miscalculation of the length of the year. Present-day astronomers calculate the mean solar year to be 365.2422 days (365 days, 5 hours, 48 minutes and 46 seconds). This is slightly shorter than the 365.25 days (365 days, 6 hours) assumed by Samuel, the third century amora and astronomer, who gave the rules for calculating the equinoxes and solstices (Eruvin 56a). This is the same assumption which is at the basis of the Julian calendar as well.
The discrepancy between the assumed length of the year and actual length may not seem like much; it is only .0078 days (11 minutes, 14 seconds) a year. Yet, over a period of a thousand years, a difference of 7.8 days (1000 x .0078) exists between a system based on assumed length (the Julian calendar or Samuel’s tequfot) and one based on actual length. It is this difference which led the Catholic Church under Pope Gregory XIII to correct the Julian calendar by dropping 10 days in 1582 (the day after Thursday, October 4 became Friday, October 15), thus creating the Gregorian calendar. To prevent further problems, three leap years were eliminated every 400 years, so that only century years divisible by 400 were leap years. This system, which eventually caught on in the whole world, is not perfect, since in 3300 years another one day discrepancy accumulates.
In Samuel’s calculation, however, there are exactly 365 ¼ days in a year, and each tequfah (solstice or equinox) lasts exactly 91 days and 7 ½ hours (despite the disparate lengths of the various seasons). One autumnal equinox (tequfat tishrei) falls exactly 365 ¼ days after the previous one. Samuel’s calculation has kept in step with the Julian calendar throughout the centuries, and, therefore, just as in Samuel’s time tequfat tishrei fell on the Julian September 24, so, too, today it invariably falls on that date. In this century, however, the Julian September 24 is the Gregorian October 7. The sixtieth day after October 7 is December 5, and one generally begins saying tal u-matar in the Maariv before December 5, namely on December 4.
So why is this year different from all other years, or at least the last three years? This is a function of the exact hour when the equinox falls. Although it is always on October 7, in a four year cycle the tequfah will come at 03:00, 09:00, 15:00 and 21:00 (check your synagogue luah for the times). The fourth year is always a Hebrew year divisible by four (5768), or the year before a civil leap year (2008); in that year, tequfat tishrei is after dark (21:00) and, therefore, it is considered the next day (October 8). Fifty-nine days later is December 6 and tal u-matar begins in Maariv of December 5. Since the coming civil year adds an additional day, next year’s calculated autumnal equinox will again fall on October 7 at 03:00, and tal u-matar will again begin in Maariv of December 4. In the nineteenth century, the prayer for rain began in Maariv of December 3 or 4; since 1900 was not a leap year, it jumped to December 4 or 5 in the twentieth century. 2100 will also not be a leap year, and in the twenty-second century, tal u-matar will begin in Maariv of December 5 or 6. Given enough time, and no calendrical reform, eventually Jews outside Israel will start praying for rain only on the eve of Passover, just in time to stop this prayer when Passover begins.
A few observations can be added to this description of the beginning time of the prayer for rain in the Diaspora. First, the same miscalculation which causes the “sixtieth day of the autumnal equinox” to move forward vis-à-vis the sun is at the base of another Jewish ritual, the once in 28 years “Blessing of the Sun” (Birkat ha-Hammah), scheduled to occur again in one year and five months on Wednesday, April 8, 2009 (coincidentally, fourteenth of Nisan, the eve of Passover; the last time was on Wednesday, April 8, 1981). In the nineteenth century, the Blessing of the Sun occurred on Wednesday, April 7, every 28 years; in the twenty-second century it will be on Wednesday, April 9, every 28 years. Despite the fact that the Blessing commemorates the cyclical repetition of the first vernal equinox at creation, it now falls 18 days after the actual astronomical equinox.
Furthermore, it is clear from the sources that each Jewish community is actually praying for rain for its own needs, and not for rain in the Land of Israel. Nevertheless, many Jews, even relatively knowledgeable ones, think that adding tal u-matar to the prayers on December 5 marks the beginning of the rainy season in Israel, not realizing that she’elat geshamim had already begun in Israel on the seventh of Marheshvan. Perhaps one of the sources of this widespread misconception is the fact that the astronomical sixtieth day of the equinox has meaning only for Iraq, if even there, and the calculated sixtieth day has no meaning anywhere. Thus, when Jews in the Diaspora start praying for rain on December 4, they mistakenly think that they are doing so for the residents of the Land of Israel.
Perhaps their prayers are still valuable. From my experience, often November is a dry month in Israel, and the winds pick up and the rain starts falling only in the first week of December. The sages tell us that the reason Israel has distinct wet and dry seasons and is so dependent upon rainfall (as compared to Egypt; cf. Deut. 11:10-12) is that God delights in hearing the prayers of the righteous who turn to Him in supplication for rain. Perhaps, the beginning of serious rain in the Land of Israel at the beginning of December, just as the prayer for rain starts in the Diaspora, is a sign that God actually delights in the prayers of the ignoramuses, who believe that their supplications for rain at that time are directed for the good of the Jews in the Land of Israel, not realizing that their prayers should be intended to bring rain to their own countries of residence. Whatever the case, we wish along with the High Priest on Yom Kippur that this year in Israel will, indeed, be very wet and not too cold, and that the rain will be only for a blessing!
 For a discussion of the Babylonian custom, and the reasons behind it, see Arnold A. Lasker and Daniel J. Lasker, "The Jewish Prayer for Rain in Babylonia," Journal for the Study of Judaism in the Persian, Hellenistic and Roman Period 15 (1984): 124-144.
 In the words of the commentary attributed to Rashi on Ta’anit 10a: “Thus we act since all our customs follow the Babylonians (kol minhageinu ahar benei bavel).”
 For a fuller description of the long process described in these few sentences, see Arnold A. Lasker and Daniel J. Lasker, "The Jewish Prayer for Rain in the Post-Talmudic Diaspora," AJS Review 9:2 (Fall 1984): 141-174.
 The equinoxes and solstices fall at the same instant all around the world, so in Israel, the autumnal equinox was at 12:51 PM; in Hawaii, at 12:51 AM; all times are daylight savings times.
 Details can be found in Arnold A. Lasker and Daniel J. Lasker, “The Strange Case of December 4: A Liturgical Problem,” Conservative Judaism 38:1 (Fall 1985): 91-99.