Medieval Latin Christian texts on the Jewish calendar: addenda and new discoveries

This article is intended to serve as a supplement to the volume Medieval Latin Christian Texts on the Jewish Calendar published in 2014. It provides references to previously neglected Latin texts and/or numerical tables related to the rabbinic lunar calendar, which appear in manuscripts copied between the twelfth and sixteenth centuries. Among the material covered are comments on the Jewish calendar in some recently published computus treatises of the twelfth century and a fourteenth-century Italian manuscript containing decision trees for the year-types in the rabbinic calendar. The article also documents the thirteenth- and fourteenth-century spread of Latin tables for finding the date/time of mean conjunction ( molad ) according to the Jewish calendar, including those contained in a work by the Franciscan John of Pershore. In addition it covers various late-medieval calendars in which conjunction times are given in the Jewish manner of dividing the hour into 1,080 ḥalakim .