The Islamic calendar or Hijri calendar (AH) is a lunar calendar consisting of 12 months in a year of 354 days. It is used to date events in many Muslim countries (concurrently with the Gregorian calendar).
Muslims use the calendar to determine days of observing the annual fasting of Ramadan, attending Hajj, as well as marking other Islamic holidays and occasions.
The first year of this calendar was the Islamic year beginning in AD 622 during which the emigration of Prophet Muhammad (PBUH) from Mecca to Medina, known as the Hijra, occurred.
The following infograph sheds light on the months of Islamic calendar, highlighting the significant religious occasions of each month.