Although the name Culāsakaraj is a generic term meaning "Lesser Era" in Pali, the term Chula Sakarat is often associated with the various versions of the calendar used in regions that make up modern-day Thailand, Laos, Kampuchea, Myanmar and the Sipsong Panna area of China.
The name Chula Sakarat is derived from Pali culā "small" and Sanskrit śaka + rāja, literally meaning "Scythian king" (the meaning was thought and held to be "era" by some of those having adopted the Indianised culture in Indochina, including the Thais).
The calendar was launched in 640 CE in Sri Ksetra Kingdom (in modern Myanmar) with the epochal year 0 date of 22 March 638.
[4] However, scholarship says the earliest evidence of Burmese calendar in modern Thailand dates only to mid-13th century.
[5] The use of the calendar appears to have spread southward to the Sukhothai, Ayutthaya, and eastward to Laotian states in the following centuries.
The only remaining independent state Siam too dropped the calendar on 1 April 1889 per King Chulalongkorn (Rama V)'s decree.
Thailand has moved on to its own version of Buddhist calendar since 1941 although the Chula Sakarat era dates remain the most commonly used and preferred form of entry by the academia for Thai history studies.
[15] Since the Thandeikta system not only does not solve but actually increases the accumulating drift issue, Burmese calendarists have resorted to periodically modifying the intercalation schedule of the Metonic cycle, starting in 1839 CE, using apparent reckoning.