The Colombo Grand Mosque announced today that Muslims across Sri Lanka will begin their Ramadan fast at dawn on Friday, May 18.

Ramadan isn’t announced until the first crescent of the new moon – known as the Hilal – is sighted, denoting the start of each month in the Islamic calendar. 

Islamic calendars are based on the moon, while the Gregorian calendar used by much of the Western world is based on the sun, so dates move around year from year.

Last year the month of Ramadan began on Friday May 26.

Ramadan is the ninth month of the Islamic calendar and is observed by Muslims worldwide as a month of fasting.