Eid al-Adha 2016: When is it and why does it not fall on the same date every year?

Eid al-Adha, the holiest celebration in the Islamic calendar, was expected to fall on 11 September, on the anniversary of the terrorist attacks on the World Trade Centre and Pentagon in 2001.

But it has been confirmed the holiday will now fall a day later, on 12 September, in most countries.

Literally translating as the “festival of the sacrifice” and also known as the “Greater Eid”, Eid al-Adha marks the end of Hajj, the annual Islamic pilgrimage to Mecca undertaken by Muslims all over the world.

It is distinct from Eid al-Fitr, the festival that comes immediately after Ramadan celebrated last month.

During the Greater Eid, Muslims commemorate the day Ibrahim was about to sacrifice his son but was told by God to kill an animal instead. The celebration symbolises Ibrahim’s devotion to Allah.

When is Eid al-Adha?

The timing of the celebration is dictated by the lunar cycle, so the festival falls on a different date every year, just as Easter does.

The day is set when a new moon is sighted – but there is no exact definition of what this means. There is little agreement within the faith about whether the moon must be spotted with the naked eye and whether it should be seen in the country where the celebrations are happening.

Saudi Arabia has been known to send up fighter jets to determine whether the new moon has arrived.

The result of the varying interpretations of the rule is that Greater Eid falls on a different day depending on what sect, mosque or region you are in.

Saudi Arabia’s Supreme Court announced on Friday it would celebrate the festival on the 12 September.

The US, Canada and the Islamic Society of North America all follow the Saudi calendar, as does the European Council of Fatwa and Research.

But in Pakistan and Bangladesh, the date is determined by local sightings of the moon. This year, the Asian countries will celebrate the Greater Eid on September 13.

Why has Eid al-Adha’s timing received so much attention this year?

Concerns arose that the holiday would be misunderstood after it initially appeared the festival would fall on the anniversary of the September 11 attacks.

The worry was that the festivities would be interpreted as Muslims celebrating the atrocities. The Muslim council on American-Islamic Relations held meetings about the possibility.

Ibrahim Hooper from the council, told Reuters he was concerned it might allow “Islam haters to falsely claim that Muslims were celebrating on 9/11”.

Following a surge in suspected hate crimes after terrorist massacres in Paris and California, religious leaders put their communities on high alert when they heard about the expected date.

Akbar Ahmed, a chair of Islamic Studies at the American University in Washington DC said: “One act of violence could trigger another as there is heightened tension."

Mosques which held outdoor prayers on Eid were reportedly considering moving indoors amid worries about security.

How is Eid al-Adha celebrated?

For Muslims, the day begins with morning prayers, followed by the exchange of food and gifts with family and friends. Muslims are obliged to share their food and money with the poor so they too can take part in the celebrations.

Worshippers will slaughter an animal, such as a sheep or a goat. In Pakistan alone, nearly ten million animals are slaughtered on Eid. Anyone wishing to sacrifice an animal in the UK must conform to welfare standards so the animal is treated humanely.

The festival is traditionally four days long, but public holidays vary depending on the country.

Turkey, Qatar, the UAE, Kuwait and Oman will have nine-day breaks.Pakistan will observe a three-day break for Eid, while Bangladesh will have six days off.

Saudi Arabia has announced a 12-day holiday public holiday, which will include the days of the Hajj pilgrimage.

But low oil prices and government spending cuts are expected to dampen Eid celebrations there.