The muslim calendar is lunar. it is also known as the islamic or hijri calendar. each month in the calendar begins with a new moon. the twelve-month calendar has 354 or 355 days and is used in many muslim countries along with the gregorian calendar. the islamic weekdays—like jewish weekdays—begin at sunset.
the islamic calendar is used to determine the proper day on which to celebrate holy days and festivals. the ninth month, ramadan, is a sacred month for muslims. during this month, they do not eat or drink anything between sunrise and sunset. at the end of this fast, the muslims celebrate with the festival of eid ul-fitr. the festival is meant to give to allah for through the fast.