During the Middle Ages, calendars played a significant role in both the Jewish and Christian communities as a means of reckoning time and structuring religious worship. Although calendars spawned a rich and extensive literature in both medieval Latin and Hebrew, it remains a little-known fact that Jews and Christians studied not only their own calendrical traditions, but also those of their respective rival group: Jewish scribes incorporated Christian material into Hebrew calendrical manuscripts, while some Christian scholars even dedicated entire treatises to the calendar used by Jews. The present article will examine these sources from a comparative perspective and use them to shed new light on the intellectual exchange that took place between Jews and Christians during the twelfth to fifteenth centuries. Particular attention will be paid to the role of oral vs. written transmission in the transfer of calendrical knowledge from one context to another. © koninklijke brill nv, leiden, 2014.
