Muslims around the world are bidding farewell to the Islamic holy month of Ramadan and will soon celebrate Eid al-Fitr.

Eid, which means “festival” or “feast” in Arabic, is a celebratory occasion for more than one billion Muslims worldwide. However, in some countries, especially multicultural ones like Australia, Muslims don’t always celebrate Eid on the same day. Here’s why.

One of two celebratory holidays in the Islamic faith, Eid al-Fitr is when Muslims come together in prayer and celebrate completing Ramadan. The "Festival of Breaking the Fast" is celebrated worldwide during the first three days of Shawwāl, the tenth month of the Islamic calendar.