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