Eid al-Adha

Eid al-Adha marks the culmination of the hajj (pilgrimage) rites at Minā, Saudi Arabia, near Mecca, but is celebrated by Muslims throughout the world. As with Eid al-Fitr, it is distinguished by the performance of communal prayer (ṣalāt) at daybreak on its first day. It begins on the 10th of Dhū al-Ḥijjah, the last month of the Islamic calendar, and continues for an additional three days (though the Muslim use of a lunar calendar means that it may occur during any season of the year).

Encyclopaedia Britannica