Thai solar calendar
The Thai solar calendar is a solar calendar that is used by Thailand. King Chulalongkorn adopted the calendar in AD 1888 to be the Siamese version of the Gregorian calendar. The years are now counted in the Buddhist Era rather than the Christian Era.
On 6 September 1940, Prime Minister Phibunsongkhram stated that 1 January 1941 would be the start of the year 2484 BE, so that year 2483 BE had only nine months. To convert dates from 1 January to 31 March before that year, the number to add or subtract is 542; otherwise, it would be 543.