In 921–22 CE, a calendrical dispute erupted between the Palestinian and Babylonian Jewish Rabbanite communities. The two communities disagreed about a small detail related to the calculation of the Jewish calendar, which usually made no difference, but that year resulted in a two-day discrepancy between the two calendars. Unable to settle the disagreement, Rabbanite Jews in Palestine and Babylonia observed Passover and Rosh Ha-shanah on different days in the spring and fall of 922. Rabbanite Jews in other parts of the Near East were forced to follow either the Palestinian or Babylonian calendar. (This dispute did not affect Karaite communities, whose calendar operated separately from the Rabbanite calendar.)
During the controversy, tensions ran high. Rabbinic authorities in Palestine and Babylonia circulated letters about why their calculations were accurate, and accused each other of calendrical mistakes. Sacha Stern, in his monograph devoted to the history of this calendrical disagreement, argues that “it was, above all, a fight for legitimacy and authority, part of a much broader struggle between Palestine and Babylonia for religious and political hegemony” (3).
The controversy did not last long. By the winter of 923, the calendars were once again synchronized, and Rabbanite Jews across the region celebrated their festivals on the same days. The controversy was remembered for a few generations, until it receded to the murkier parts of Jewish memory. By the thirteenth century, it had been entirely forgotten, its details only rediscovered in the late nineteenth century in the documents of the Cairo Geniza.
Early studies of the Geniza documents by Hayim Yehiel Bornstein (1845–1928) presented the controversy as a disagreement between the famous Babylonian rabbi Sa‘adiah Gaon and the less well-known head of the rabbinic academy in Tiberias, Aharon ben Meir. According to Bornstein, this represented the last calendrical dispute before the finalization of the fixed rabbinic calendar. Notwithstanding significant advances since his time in Geniza studies, the history of the Jewish calendar, and the field of social history, Bornstein's conclusions have generally been accepted, although new manuscripts regarding this calendar controversy have been discovered, and different assumptions made about calendars and communal boundaries.
Stern's book offers a fresh assessment of this calendar controversy and its enduring significance. It reproduces all of the extant texts related to this event, newly edited and translated, with tables, glossary, critical apparatus, analysis of the material features of the manuscripts, and commentary, correcting earlier editions and incorporating new manuscript finds; for these sections alone, the book is a great resource. Moreover, Stern's monograph takes an important methodological stance, arguing that “written sources cannot serve as historical evidence … except insofar as they are authentic expressions of (individual or collective) subjective perspectives, at the time, on the historical environment and events. It does not matter, therefore, that the sources are biased; quite on the contrary, it is precisely the personal bias, the rhetorical agenda, the literary devices that constitute our historical material. They were integral, indeed, to the controversy itself” (xi). In addition to reconstructing the positions expressed during the controversy, Stern demonstrates its memory's continued significance through the eleventh century, when many of the manuscripts were copied—evidence that communities sought to preserve and transmit traditions about this dispute even after it had been resolved.
Stern's book is divided into four parts. The first chapter in part 1 offers an updated narrative of the controversy, based on meticulous analysis and synthesis of all available manuscripts. During Sukkot, the Palestinian rabbinic leader annually announced the upcoming year's calendar and festival dates so that the community knew in advance the details of the calendar. Even though Babylonian rabbinic figures typically performed their own calendrical calculations independently, they accepted the authority of the Palestinian community to announce the calendar. At some point, however, the Babylonians began making their own calendrical announcements in Elul, anticipating the Palestinian announcement by about a month. The two communities usually announced identical calendars—until 921 CE, when the Palestinian calendar, to be announced by Ben Meir's son in Jerusalem, was rumored to differ from the calendar already announced by the Babylonians in Baghdad. While Ben Meir calculated that the months of Marheshvan and Kislev ought to be defective (consisting of twenty-nine days), the Babylonians insisted that these months be full (consisting of thirty days), thus misaligning the calendars by two days. When efforts to reconcile the differences between the calendars failed, each side turned to convincing Jewish communities in the region to follow their calendar while bitterly polemicizing against their opponents. The Babylonians eventually authored a memorandum of the controversy to explain the dispute and articulate their position on the contested calendrical calculations.
Among Stern's arguments is that Sa‘adiah was a marginal figure in this controversy, rather than the author of the most well-known text related to it, as has previously been assumed. The text was authored, according to Stern, by the Babylonian exilarch and the leaders of the Babylonian academies. (Sa‘adiah was not yet in a leadership position in the Babylonian academy.) Stern also challenges the assumptions that the Babylonians triumphed in the dispute and that the rabbinic calendar was finalized by the end of the dispute. Stern claims, rather, that the dispute ended simply because no one had energy to continue arguing, especially after the calendars naturally aligned the following year. Stern observes that Palestinian and Babylonian rabbinic authorities likely continued to conduct their distinct calendrical calculations until the early twelfth century, especially given that the difference in calculations did not make any practical difference during most of those years (with the exception of 927). Eventually, the Palestinian tradition did decline, such that by 1108 (the next year when the difference in calculations would have resulted in competing calendars) it was the Babylonian calendrical calculations that were used to set the Jewish calendar, but this decline was not a direct or immediate consequence of the controversy of 921.
The remaining chapters in part 1 review previous scholarship, offer an explanation of how the manuscripts have been collected and analyzed, and provide a precise account of the calendrical controversy. Part 2 consists of an introduction, critical edition, and diplomatic editions of the main text about the controversy, which Stern has retitled The Book of the Calendar Controversy (formerly called The Book of the Festivals). Part 3 provides editions of contemporaneous letters and other polemical writings, while part 4 compiles sources related to the controversy from the subsequent two centuries. Several of these sources have not been studied in relation to this controversy, and so this volume presents an unprecedented compilation of materials about this event and its long-lasting significance.
Scholars of medieval Jewish history, the Cairo Geniza, the Jewish calendar, and those interested in the role of calendars in religious communities will all find this book of interest. Despite its philological focus, the book is written in an accessible tone and its arguments extend beyond the specific texts it analyzes. Over the past two decades, Stern has produced an impressive corpus of scholarship on the history of the Jewish calendar. This latest book builds upon insights about timekeeping gained from these earlier studies, but rather than constructing a macrohistory across the longue durée, as Stern has done previously with much success, it highlights how much can likewise be learned by microhistorically analyzing one specific calendar in one particular year and its lasting legacy on Jewish calendrical history.
