Adar is the fifth month of the Jewish calendar, usually falling around February and/or March of the Gregorian calendar. The holiday of Purim falls on the 14th of Adar. The Jewish calendar requires, every two or three years, a "leap month," and when this occurs, there are two Adars, Adar Aleph and Adar Beit. Purim falls during Adar Beit if there are two Adars in a given year.