the lunar calendar used by Muslims and reckoned from a.d. 622: the calendar year consists of 354 days and contains 12 months: Moharram, Safar, Rabi I, Rabi II, Jumada I, Jumada II, Rajab, Shaban, Ramadan, Shawwal, Dhu ʾl-Qaʿda, and Dhu ʾl-hijjah. In leap years the month Dhu ʾl-hijjah contains one extra day.
