The Islamic calendar, Muslim calendar or Hijri calendar (Anno Hegirae or AH, Arabic: التقويم الهجري at-taqwīm al-hijrī) is a lunar calendar consisting of 12 months in a year of 354 or 355 days.
It is used to date events in many Muslim countries (concurrently with the Gregorian calendar), and used byMuslims everywhere to determine the proper days on which to observe the annual fasting, to attend Hajj, and to celebrate other Islamic holidays and festivals.
The first year was the Islamic year beginning in AD 622 during which the emigration of Muhammad fromMecca to Medina, known as the Hijra, occurred. Each numbered year is designated either "H" for Hijra or "AH" for the Latin Anno Hegirae ("in the year of the Hijra"); hence, Muslims typically call their calendar the Hijri calendar.
The current Islamic year is 1438 AH. In the Gregorian calendar, 1438 AH runs from approximately 3 October 2016 to 21 September 2017.