Singapore celebrates 11 national holidays each year. National holidays are governed under the Employment Act of Singapore and enforced by the Ministry of Manpower. The Ministry of Manpower is given the authority to create one time national holidays and to petition the government for new holidays under these laws.
A majority of the holidays celebrated in Singapore are based on different religious beliefs. Many of these holidays occur on different dates each year because they are based on different calendars and the lunar cycle. The Ministry of Manpower will release the official holiday dates towards the end of each year for the following year.
Christian holidays that use the lunar cycle are based off of the Gregorian calendar. Muslim holidays based off of the lunar cycle in Singapore are calculated by the Majlis Ugama Islam lunar visibility criteria. Hindu holidays are based off of the Hindu lunar calendar. If more than one holiday occurs on the same date because of lunar calculations, an additional holiday is given to replace it and to eliminate "bad luck".