Latin Authors Discuss the Jewish Calendar

Abstract

Why would Latin authors between twelfth and fifteenth century take an interest in Jewish calendar? Mainly for two reasons. Its times for mean conjunctions of Sun and Moon (molad s) were much more precise than could be had from Christian ecclesiastical computus, so they would contribute to a better determination of Easter. Also, Jewish calendar (known in its present form since tenth century) was believed to have been valid already in biblical times, so that it was proper one to use for determining biblical datings, rather than Roman calendar. In short, main fields of interest were calendar reform and biblical chronology, topics touched on very often in medieval literature (cf. luminaries like Roger Bacon). There are also several Latin texts especially dedicated to Jewish chronology for one purpose or other. The earliest of these (Reinher of Paderborn, Compotus emendatus , composed in 1171) saw its first printing as recently as 1951, and again in 2011.The present work edits five further special treatises, apparently only ones of their kind before sixteenth century. They are so varied in form and content that each requires special editing, which this editor has done very conscientiously. The diverse texts includeLiber erarum (1188/91), a 12-page anonymous tract known from six manuscripts (thirteenth to fifteenth century) and a print from 1549; there is no modern edition until now. It contains a list of traditional eras (Spanish, Seleucid, Persian, Christian, Arab) relative to date 23 March 1191. It also offers data for Cremona, suggesting a connection with Gerard translator. However, editor judges it to be reworked from an original in Hebrew by a Jewish author. The text is purely computational, describing Hebrew chronological system and giving rules for finding molad for beginning of each lunar year and for various other times.Robert of Leicester, De compoto Hebreorum aptato ad kalendarium (1294), 65 pages in edition, known from two manuscripts of early to mid-fourteenth century. Not previously printed. It is the lengthiest and most sophisticated Latin treatise on Jewish calendation to be extant from Middle Ages, according to editor (p. 13), and edition is elaborate, including extensive notes on sources. The author's stated intention is to obtain knowledge of bygone ages, i.e., Biblical chronology, with Jewish calendar as a tool. So first we get a technical account of Jewish time reckoning, rules for converting Jewish into Julian dates, and finally datings of Creation, Noah's flood, exodus from Egypt, destruction of First Temple, conception of John Baptist and incarnation and crucifixion of Jesus. Robert also discusses controversy about whether Last Supper was performed with leavened or unleavened bread, a factor in Great Schism of 1054.Nicholas Trevet O.P., Compotus Hebreorum (1310), 13 pages in edition, known from one, early fourteenth-century manuscript. Not previously printed. The text is appended to a commentary on Leviticus and is meant to put feasts mentioned there into a calendrical framework. In fact, it mainly gives rules for finding weekdays for these feasts in a particular year of Jewish era. …