Editing Saadia Gaon (section)

===Dispute with Ben Meir===
In 922, six years before Saadia was appointed Gaon of Babylonia, a controversy arose concerning the [[Hebrew calendar]], that threatened the entire Jewish community. Since [[Hillel II]] (around 359 CE), the calendar had been based on a series of rules (described more fully in [[Maimonides]]' Code<ref>Laws of the Sanctification of the Moon, chs. 6-10, written c. 1170.</ref>) rather than on observation of the [[lunar phase]]s. One of these rules required the date of [[Rosh Hashanah]] to be postponed if the calculated [[lunar conjunction]] occurred at noon or later. Rabbi [[Aaron ben Meïr]], head of the [[Palestinian Gaonate]] (then located in [[Ramla]]), claimed a tradition according to which the cutoff point was 642/1080 of an hour (approximately 35 minutes) after noon.{{cfn|Various suggestions have been made as to where Ben Meir got this figure. A contemporary author, Remy Landau, suggests that he wanted to optimize the rule and thereby reduce the frequency of this postponement: {{cite web |title=Hebrew Calendar Science and Myths |url=http://www.geocities.com/Athens/1584/index.html |date=7 March 2000|archive-url=https://web.archive.org/web/20000307015735/http://www.geocities.com/Athens/1584/index.html |archive-date=2000-03-07 }}|date=July 2024}} In that particular year, this change would result in a two-day schism with the major Jewish communities in Babylonia: according to Ben Meir the first day of Passover would be on a Sunday, while according to the generally accepted rule it would be on Tuesday.

Saadia was in [[Aleppo]], on his way from the East, when he learned of Ben Meïr's regulation of the Jewish calendar. Saadia addressed a warning to him, and in Mesopotamia, he placed his knowledge and pen at the disposal of the exilarch [[David ben Zakkai]] and the scholars of the academies, adding his letters to those sent by them to the communities of the [[Jewish diaspora]] (922). In Babylonia, he wrote his ''Sefer haMo'adim'', or "Book of [[Jewish festivals|Festivals]]", in which he refuted the assertions of Ben Meïr regarding the calendar and helped to avert from the Jewish community the perils of schism.