fully adopted in 1853. The first adjustment to then existing Metonic Cycle was made by putting an intercalary month in 1201 ME (1839 CE) instead of 1202 ME (1840). While the new system has seemingly narrowed the gap between the calendar's solar and lunar years, it has not made the calendar more accurate when compared against the actual tropical year. Indeed, it is slightly worse than the old system. (The Thandeikta solar year is about 23 minutes 51.4304 seconds ahead of the mean solar year whereas Makaranta is about 23 minutes 50.8704 seconds ahead.) As a result, the calendar has kept on drifting away from the actual solar year. The calendarists have periodically resorted to modifying its intercalation schedule, based on apparent reckoning, to keep pace, at the expense of making publishing future calendars more than a few years out all but impossible. In sum, at various times the calendar has used at least three slightly different methods of calculation to determine the insertion times of the intercalary day and month. Current status The calendar fell out of official status in several mainland Southeast Asian kingdoms (except Burma) in the second half of the 19th century with the arrival of European colonialism. The Gregorian calendar replaced the Burmese calendar in Cambodia in 1863 and Laos in 1889. In 1889, the only remaining independent kingdom in Southeast Asia, Siam, also replaced the Burmese calendar and switched to the Gregorian calendar as the official civil calendar and the Ratanakosin Era (with 1782 CE as Year 1) as the traditional lunisolar calendar. In Burma (Myanmar), the Burmese calendar has not been replaced, but used alongside the Gregorian calendar after the fall of the Burmese kingdom. Thailand has moved on to its own version of the Buddhist calendar since 1941, although the Chulasakarat era dates remain the most commonly used and preferred form of entry in academia for historical studies. The Chittagong Magi-San calendar, identical to the Arakanese calendar, is still used by certain ethnic minorities of Bangladesh. Today, the Calendar Advisory Board within the Ministry of Religious Affairs and Culture of Myanmar is tasked with keeping the lunisolar calendar in line with the solar year. Structure Day The calendar recognises two types of day: astronomical and civil. The mean Burmese astronomical day is from midnight to midnight, and represents 1/30 of a synodic month or 23 hours, 37 minutes and 28.08 seconds. The