The Islamic or Hijri calendar is based on a lunar month of 29 to 30 days, with the day starting at sunset. The Islamic year consists of twelve months: (1) Muharram, (2) Safar, (3) Rabi` Awwal, (4) Rabi` Thani, (5) Jumada Awwal, (6) Jumada Thani, (7) Rajab, (8) Sha`ban, (9) Ramadan, (10) Shawwal, (11) Dhul- Qi`dah, and (12) Dhul- Hijjah.