(Akkad.
Nisannu). First month of the Jewish religious
Calendar; seventh month of the Hebrew civil year counting from
Tishri. It is a "full" month of 30 days and normally coincides with March-April. Its sign of the zodiac, Aries the Ram, was associated by the rabbis with the paschal lamb. Nisan is called "the first of the months of the year" (Ex. 12:2), but in the Pentateuch (Ex. 13:4, 23:15, 34:18; Deut. 16:1) it is generally known as Abib (Heb.
ḥodesh ha-Aviv, "the month of spring"). Nisan was the designation adopted by Jews returning from the Babylonian
Exile. It appears in later biblical sources (Est. 3:7; Neh. 2:1) as well as in the Apocrypha. Nisan's place at the head of the religious calendar may be linked with the Mishnaic statement that its first day is "the new year for kings and festivals" (
RH 1:1).
The Israelite departure from Egypt took place in mid-Nisan, and in ancient days messengers were dispatched by the Sanhedrin to announce the precise time for the observance of Passover (RH 1:3). Passover is celebrated on 15-21 Nisan in Israel (on 15-22 Nisan in the Diaspora), and the counting of the Omer begins on the second night of the festival. According to the Bible (Ex. 40:17), the Tabernacle was erected in the wilderness on the first (New Moon) of Nisan; on the tenth, a generation later, the Israelites crossed the Jordan to occupy the Promised Land. Traditionally, 15 Nisan marks the beginning of the harvest season in the Land of Israel (BM 106b). Holocaust Memorial Day (Yom ha-Sho'ah) is today observed in Israel on 27 Nisan (in Diaspora communities, however, on 19 April). Fasting, funeral eulogies, and public displays of mourning are prohibited throughout the month, since it is zeman ḥerutenu ("the Season of our Freedom") commemorating Israel's redemption from slavery.