In Judaism, the New Moon ushers in a new month

Rosh Chodesh or Rosh ḥodesh (Hebrew: ראש חודש‎; trans. Beginning of the Month; lit. Head of the Month) is the name for the first day of every month in the Hebrew calendar, marked by the appearance of the new moon. The new moon is marked by the day and hour that the new crescent is observed. It is considered a minor holiday, akin to the intermediate days of Passover and Sukkot.^[1]