There are two official celebrations in Islam, Eid al-Fitr and Eid al-Adha. Both holidays occur on dates in the lunar Islamic calendar, which is different from the solar-based Gregorian calendar, so they are observed on different Gregorian dates every year. There are a number of other days of note and festivals, some common to all Muslims, others specific to Shia Islam as a whole or branches thereof.
Eid al-Fitr ‘Feast of Breaking the Fast’, is celebrated by Muslims worldwide because it marks the end of the month-long dawn-to-sunset fasting of Ramadan. It 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 day is known under various other names in different languages and countries around the world. The day is also called Lesser Eid, or simply Eid. Eid al-Fitr has a particular salat (Islamic prayer) that consists of two rakats (units) generally performed in an open field or large hall.
Eid al-Adha honors the willingness of Ibrahim (Abraham) to sacrifice his son Ismael as an act of obedience to God’s command. Before Ibrahim could sacrifice his son, however, God provided a lamb to sacrifice instead. In commemoration of this intervention, animals are sacrificed ritually. One-third of their meat is consumed by the family offering the sacrifice, while the rest is distributed to the poor and needy. Sweets and gifts are given, and extended family is typically visited and welcomed. The day is also sometimes called Big Eid or the Greater Eid. In the Islamic lunar calendar, Eid al-Adha falls on the 10th day of Dhu al-Hijjah and lasts for four days. In the international (Gregorian) calendar, the dates vary from year to year, shifting approximately 11 days earlier each year.
This video of the night celebrations and morning prayer was shot at Kochangadi, Kerala.