||Liturgy for the new moon. The prayer of thanksgiving is recited at the periodical reappearance of the moon's crescent. In Hebrew, the prayer is known by several names: Birkat ha-Levanah ("the blessing of the moon") or Kiddush Levanah ("sanctification of the moon"). It can be recited front the third evening after the appearance of the new moon until the 15th of the lunar month; after that day, the moon begins to diminish. The prayer is recited only if the moon is clearly visible (not when it is hidden by clouds) and it should preferably be said in the open air. According to the Talmud (Sanh. 42a), "Whoever pronounces the benediction over the new moon in its due time welcomes, as it were, the presence of the Shekhinah" ("Divine Presence") and hence it is recommended (Sof. 20:1) to pronounce the benediction, if possible, on the evening after the departure of the Sabbath when one is still in a festive mood and clad in one's best clothes.
The blessing of the new moon and the festive character of Rosh Hodesh (New Month) originated in the time of the Second Temple. Due to the significance of the moon in the Jewish calendar (see Ex. 12:2), it may be of much older origin; in the course of time it has, however, undergone substantial changes. The rite takes the moon as a symbol of the renewal in nature as well as of Israel's renewal and redemption. Various other elements, some of them of a kabbalistic nature, have become attached to the rite.