A primitive rabbinic calendar text from the Cairo Genizah

A hitherto unnoticed fragment from the Cairo Genizah, T-S K2.27, describes two methods for calculating the calendar that ignore the molad and differ in further ways from the later, fixed rabbinic calendar. These 'primitive' rabbinic calendars, which I would date to the eighth century at the latest, are based on calendar rules attested in the Palestinian Talmud but also attempt, not very accurately, to turn the Jewish calendar into a fixed cycle. These calendars represent an early attempt to fix the Jewish calendar. They may be seen as a missing link between the empirical, new moon-based calendar of Mishnaic and Talmudic sources and the molad calendar that became standard in the later medieval period. They also suggest that the fixed rabbinic calendar was originally formed in the early Middle Ages by emulation of the Christian Easter cycles.