Rosh Chodesh, the day a new Jewish month begins, is a minor festival. Because the Jewish calendar is based on the cycles of the moon and then adjusted according to the seasons, Jewish months begin on the new moon (that is, when NO moon is showing, despite the photo at right!)

In Biblical times, the Israelites made sacrificial offerings and sounded the Shofar (ram's horn) to mark the day. Women abstained from work as a symbolic recognition of the women of Israel who refused to give up their jewelry to make the Golden Calf (the idol made when Moses was on Mount Sinai).

Some traditional women today will still refrain from work on Rosh Chodesh. Some men will do their wife's work as a tribute to women everywhere, recalling their strength in not succumbing to the idolatry of the Golden Calf. The holiday has been claimed by the Jewish women's movement. Jewish women often gather to study and pray on Rosh Chodesh as a celebration of women.

The day also serves as a time for renewal and reflection for many Jews. It is a day to think about the previous month, what errors one made and how the next month may be made better. Some people will serve a new food on Rosh Chodesh as a sign of renewal.