Most countries have a fixed date National Day, but some have movable dates. An example here is Jamaica, which celebrates its National Day on the first Monday in August. This commemorates independence from the United Kingdom which was attained on Monday, 6 August 1962 - the first Monday in August of that year. Another example is Thailand which celebrates the birthday of the King on 5 December. This date will change on the accession of the heir to the throne.