Eid al-Adha in Islam. Aid al-kabir (the greater aid) also called Eid al-Adha is one of the two most important Islamic festivals, Eid al-Adha begins on the 10th day of Dhu'l-Hijja, the last month of the Islamic calendar.id Al Adha will be celebrated this year on 24 September 2015 (+-1 day), the Festival of Sacrifice is a religious festival celebrated by Muslims, Eid ul-Adha annually falls on the 10th day of the month of Dul Hijja of the lunar Islamic calendar. Share this article: