First Month Of The Year Hebrew Calendar. Tishrei, the first month of the jewish year, is replete with holidays. The rabbis who first began working out the jewish calendar in the fourth century ce recognized that limiting all months to either 29 or 30 days wasn't going to.
Such a year is called a shanah meuberet (pregnant year) in hebrew; Tishrei is the first month of the hebrew calendar and usually falls in september or october.