“Rosh Chodesh” {ראש חודש} is Hebrew for “the beginning of the month” and it literally means “the head of the month.” In Judaism, the first day of every month in the Hebrew calendar is marked by the birth of a new moon. “Rosh Chodesh” is considered a holiday but it is different than the Sabbath and other major holidays. The origin of this tradition is mentioned in the Bible, in the Book of Numbers:
“On the day of your gladness also, and at your appointed feasts and at the beginnings of your months, you shall blow the trumpets over your burnt offerings and over the sacrifices of your peace offerings. They shall be a reminder of you before your God: I am the LORD your God.” (Numbers 10:10)