Thai solar calendar

The epoch (reference date) for Year 1 was 6 April 1782 with the accession of Rama I, the foundation of the Chakri dynasty, and the founding of Bangkok (Rattanakosin) as capital.

In Thailand the sacred, or Buddhist Era, is reckoned to have an epochal year 0 from 11 March 543 BC, believed to be the date of the death of Gautama Buddha.

[1] As previously noted, Rama VI moved the start of the year back to 1 April in 2455 BE, 1912 CE, so that 130 R.S.

In the traditional Thai calendar, the change to the next Chinese zodiacal animal occurs at Songkran (now fixed at 13 April.

The day added to February in a solar leap year is Athikasuratin (อธิกสุรทิน, respelled to aid pronunciation (อะทิกะสุระทิน) from Sanskrit adhika : additional; sura : move).

[5] Using Buddhist era could easily cause confusion between itself and Anno Domini in the historical context.

For example, many Thai people regard the establishment of the Ayutthaya Kingdom to be in 1350, which is direct conversion from Buddhist era 1893, while the actual date is 1351.