Eid Al-Adha 2015: When is it and why is the celebration important to Muslims?

The festival is the second of two religious holidays celebrated by Muslims

An aerial view shows the Kaaba at the Grand mosque in the holy city of Mecca, on October 27, 2012. Muslims worldwide celebrate the Eid al-Adha or the Feast of the Sacrifice, marking the end of the hajj pilgrimage to Mecca and commemorating Abraham's willi (FAYEZ NURELDINE/AFP/Getty Images)

Muslims around the world will celebrate Eid al-Adha, known as the Feast of Sacrifice or the Greater Eid, with prayers, feasts and visits to family and friends.

What is Eid al-Adha?

Eid al-Adha is the second of two religious holidays celebrated by Muslims worldwide each year (the other being Eid al-Fitr).

It marks the end of the pilgrimage, or Hajj, to Mecca.

What does the Hajj involve?

The Hajj involves a pilgrimage to Mecca, Islam's holiest site.

According to the Koran, all Muslims who can afford to make the journey to Saudi Arabia should do so at least once in their lives.

Each year, at least two million Muslims will make the pilgrimage.

Why is Eid al-Adha important to Muslims?

The festival honours the willingness of Ibrahim (Abraham) to sacrifice his son, Ishmael, as an act of submission to God.

According to the Koran, as Ibrahim was about to kill his son, God stopped him and gave him a lamb to sacrifice instead.

What typically happens?

Muslims all over the world will sacrifice a cow, goat or sheep. The meat is then divided in three and shared among family, friends and the poor.

In Britain, the animal must be killed at an official slaughterhouse.

Many Muslims will send cards to family members, friends and business associates and also give gifts to children.

Other Muslims give money to charity while mosques may arrange communal meals.

When will the celebrations take place?

In the lunar-based Islamic calendar, Eid al-Adha falls on the 10th day of Dhu al-Hijah, the 12th and final month in the Islamic calendar.

As the exact day is based on lunar sightings, the date may vary between different countries.

In the UK, it is expected to take place on Thursday 24 September and last four days.