A Table of New Moons from 1501 to 1577 in a Hebrew Fragment Preserved in the John Rylands Library

A hitherto unknown set of two tables, preserved on a single sheet inscribed on both sides in Hebrew, which was originally in the Cairo Geniza, is presented and analyzed. The purpose of these anonymous tables is to convert dates from the Jewish calendar to the Julian calendar for a 76-year cycle, beginning in 1501; the underlying method seems to be unprecedented. The basic information for each year is the date in March in the Julian calendar that corresponds to 1 Nisan in the Jewish calendar. It is suggested that Abraham Zacut (d. 1515) is the author of these tables.