Sun rises behind a minaret on Abu Dhabi- Dubai highway.

Saudi Arabia announced on Sunday that Eid al-Adha, one of two important religious holidays observed by Muslims around the world, will start on Thursday, September 24, a day earlier than expected, Al Arabiya News Channel reported on Sunday.

The announcement was made after the kingdom’s official moon-sighting body watched for the Dhul Hijjah crescent, which is the twelfth and final month in the Islamic calendar.

The Islamic lunar calendar depends on sightings of the moon – a practice which can at times prove difficult.

Eid al-Adha honors the willingness of Abraham to sacrifice his promised son, Ishmael as an act of submission to God’s command. It is separate from Eid al-Fitr, which marks the end of the fasting month of Ramadan.

Eid celebrations start after the descent of the pilgrims performing from Mount Arafat, a hill east of Makkah. Eid sacrifices – where an animal, often a goat, is slaughtered – may take place until sunset on the 13th day of Dhul Hijjah.