359 ON JESUS’ LAST SUPPER before, a “Sabbath”, was the very day of Passover (Nisan 15th), according to the ancient meaning of the term 24 (see Deut 5,12.15). The discrepancy could be solved thanks to a Persian writer, Al- Biruni 25 (XI cent. CE). In a book on astronomy and calendars, he mentions a Jewish sect called Maghariyya (“ Cave-dwellers ”, in Arabic), who insisted that the year begin on a Wednesday. The sect was given that name, because of the finding of its documents in the Qumran caves in the VII cent. CE With this information the problem is resolved, since the 26th of the first month always falls on the Sunday that follows the week of the Unleavened Bread: the Covenanters were using the solar calendar of Jubilees — a conclusion that was later confirmed by other documents. Then came A. Jaubert, who started from the hypothesis that the solar calendar was once a biblical feature, before being dropped at a later stage. She first observed in the narrative of Jubilees that the numerous dated activities or travels never occurred on the 4th of the first month, nor on the 11th of the same month, and so on from week to week. Taking these to be Sabbaths, she found that the beginning of the year, I/1st, always fell on a Wednesday, thus independently confirming Al-Biruni’s statement. It appeared, too, that the significant events always occurred on a Sunday, a Wednesday, or a Friday. Then she proceeded to look for signs of such a calendar in two directions: in the Bible and in early Christian writings. Events in the Biblical narratives are less often dated than in Jubilees, but for those given with numbered, unnamed, months the pattern of Sabbaths and special days applies, especially in the Hexateuch and Ezekiel; it is a feature that may have existed before any systematic calendar. This general view has been accepted by Essenes ”) bribed false witnesses of the new moon so that Pentecost may fall on a Sunday. See A. LEMAIRE, “Le sabbat à l’époque royale israélite”, RB 80 (1973) 24 161-185 ; H. & J. LEWY, “The Origin of the Week and the Oldest West Asiatic Calendar ”, HUCA 17 (1943) 1-152. Detected by D. BARTHÉLEMY, “Notes en marge de publications récents 25 sur les manuscrits de Qumrân”, RB 59 (1952) 199-203, who stated that the Jubilee calendar was not utopic. Al-Biruni received his information from the Cairo Karaïtes, see S. POZNANSKI, “The Karaite Literary Opponents of Saadiah Gaonin ”, Karaite Studies. Edited with Introductions (ed. P. BIRNBAUM) (New York 1971) 131-234.