New Moon, (Hebrew: “Head of the Month”), the start of the Hebrew month, a minor Jewish festival on which fasting and mourning are not allowed. The modern observance consists principally in preserving the ancient custom of reciting a blessing on the Sabbath preceding the New Moon and in singing or reciting an abbreviated form of the Hallel psalms on the New Moon itself. In Old Testament times, Jews visited the Temple of Jerusalem for a special sacrifice, held a family celebration, and generally abstained from business and work.