Calendar and Community

Abstract

Traces the development of the Jewish calendar—how months and years were reckoned—from its earliest descriptions in the second century b.c.e. until it reached, in the tenth century c.e., to its present form. Solar and lunar calendars are attested in the early period, but by the first century c.e., the Jewish calendar had become predominantly lunar. A wide range of sources (literary, documentary/epigraphic, Jewish, Graeco‐Roman, and Christian) reveals, however, that Jewish communities in Palestine and the diaspora reckoned their lunar calendar independently from one another, and hence, would often celebrate the same festivals at different times. This diversity persisted until the end of antiquity, although some general trends can be identified. Until the first century c.e., Jewish lunar calendars tended to be late in relation to the solar year, and Passover would always occur after the spring equinox; whereas, by the fourth century, intercalations were adjusted in such a way that Passover was frequently earlier. In the fourth century, moreover, many communities began to calculate the day of the new moon instead of relying on observation of the new crescent, as had previously been the norm. The change from observation to calculation is particularly evident in the case of the rabbinic calendar, for which there is more evidence than any other Jewish calendar. Largely under pressure from the Babylonian rabbinic community, the rabbinic calendar gradually evolved from the third century c.e. into a fixed, calculated calendar, which became dominant in the Jewish world by the tenth century. The general evolution of the Jewish calendar throughout our period, from considerable diversity (solar and lunar calendars) to unity (a single, normative rabbinic calendar), can be explained as epitomizing the emerging solidarity and communitas of the Jewish communities of late antiquity and the early medieval world.