Jewish calendar

Jewish calendar is a lunisolar calendar used by Jews and the followers of Judaism, now predominantly for religious purposes. It is used to reckon the Jewish New Year and dates for Jewish holidays, and also to determine appropriate public reading ofTorah portions, Yahrzeits (dates to commemorate the death of a relative), and daily Psalm reading, among many ceremonial uses. Originally the Hebrew calendar was used by Jews for all daily purposes. During the era of the Roman occupation (1st century BCE), Jews began additionally following the imperial civil calendar for civic matters such as the payment of taxes and dealings with government officials.

The principles of the Hebrew calendar are found in the Torah, which contains several calendar-related commandments, including God's commandment during the Exodus from Egypt to fix the month of Aviv as the first month of the year. The Babylonian exile in the 6th century BCE influenced the calendar, including the adoption of Babylonian names for the months.