Eid-ul-Adha (the Festival of Sacrifice) is celebrated throughout the Muslim world as a commemoration of Prophet Ibrahim's (PBUH) willingness to sacrifice his son for God. Eid-ul-Adha is celebrated on the tenth day of the month of Zul-Hijja.
Eid ul-Adha annually falls on the 10th day of the month of Dhul Hijja (ذو الحجة) of the lunar Islamic calendar. The festivities last for two to three days or more depending on the country. Eid ul-Adha occurs the day after the pilgrims conducting Hajj, the annual pilgrimage to Mecca in Saudi Arabia by Muslims worldwide, descend from Mount Arafat. It happens to be approximately 70 days after the end of the month of Ramadan.