The Jewish religious year is the cycle of Sabbaths and festivals in Judaism that is rooted in the Hebrew Bible. The Jewish calendar is a lunisolar calendar, which means it is regulated by the positions of both the Moon and the Sun. The calendar usually consists of 12 alternating lunar months, each with 29 or 30 days, resulting in 353, 354, or 355 days per year. To align with the solar year, leap years are incorporated by adding a 30-day month called First Adar before the month of Adar. Leap years have either 383, 384, or 385 days and occur seven times in a 19-year cycle.
Key observances in the Jewish year include Rosh Hashanah (New Year), Yom Kippur (Day of Atonement), Passover (Pesach), Shavuot, and Sukkot. These holidays and festivals are tied to the Jewish calendar and are observed in homes and synagogues following Jewish law and custom. The weekly Sabbath, from sundown on Friday to nightfall on Saturday, is an essential day of rest in the Jewish religious calendar.