Eid al-Fitr is the earlier of the two official holidays celebrated within Islam . While the Qur'an does not mention the celebration of Eid, the religious holiday of Eid al-Fitr is celebrated by Muslims worldwide because it marks the end of the month-long dawn-to-sunset fasting of Ramadan. Some Muslims, however, do not view it as a sacred holiday. Eid al-Fitr falls on the first day of Shawwal in the Islamic calendar; this does not always fall on the same Gregorian day, as the start of any lunar Hijri month varies based on when the new moon is sighted by local religious authorities. The holiday is known under various other names in different languages and countries around the world. The day is also called Lesser Eid, or simply Eid.