Southeast Asian Intercalation: Variations and Complexities

One of the constant problems for historians of Southeast Asia is to assimilate its system of adding extra days and extra years to the lunar calendar to make it keep pace with the solar calendar. It is well known that the addition of an extra month should take place 7 times in every 19 years (adhikames), and that the addition of an extra day should occur 11 times in every 57 years (adhikawan). It is also known that the extra month is called second Ashadha and that in Thailand and Cambodia the extra day is given to the previous month, Jyestha.