Eid ul Adha
Eid ul Adha is the festival of sacrifice. It falls on the 10th of Dhu al-Hijjah, during the Hajj, and commemorates Ibrahim's willingness to sacrifice his son, whom Islamic tradition identifies as Ismail.
Those who are able offer a sacrifice and share the meat with family, neighbors, and people in need. The day includes a communal prayer.
Dhu al-Hijjah is a lunar month, so the civil date moves each year and can shift with moon sighting. The tile below shows the next occurrence.
The day before is the Day of Arafah, the 9th of Dhu al-Hijjah, the central day of the Hajj. The sacrifice is called udhiyah, and also qurbani.