101. The Burmese Calendar is essentially a religious one. "The reason given in Maha Wagga why the Wa, or Buddhist Lent, was instituted by Buddha appears to be to prevent the Bhikkus from going on their travels during the rainy season, so that they might not crush the green herbs, hurt the vegetable life, and destroy the lives of many small insects. And the Wa (Vassa), or the retreat, was prescribed to be entered upon in the rainy season for three months." (The Arakanese Calendar, by Htoon Chan; Introduction, page i). Lent begins on the first waning of Wazo or Second Wazo.
102. The direction that the Labyi of Wazo or Second Wazo should fall on a day on which the moon's longitude is at least 266° 40′ is almost exactly equivalent to a direction that the month in which solar new year's day falls should always be the month of Tagu. This is the Hindu rule, viz., the month in which the sun enters Mesha must be called Chaitra.
103. Whether that Hindu rule has any religious significance I know not, but it is evident that however suitable the year of the Surya Siddhanta may be for Hindus, it is not suitable for Buddhists. The rule that the months of Lent, viz., Wazo, Wagaung, Tawthalin and Thadingyut, shall fall in the rainy season cannot be permanently carried out by observing any year except the tropical year.
104. The tropical year (ayana hnit) was known to the author or authors of Thandeikta, but they make no use of it except to calculate the lengths of days and nights. The equinox is said to have coincided with Thingyan Kya about 207 years before Poppasaw's epoch, i.e., about 411 A. D. which is pretty near the truth. The precession is stated to be 54″ per annum, which is not correct. The real rate of precession is about 50″ per annum.
105. The Thandeikta solar year is
365 days 6 hours 12 minutes and 36.56 seconds = 365.2587564814 days.
This is proved by modern science to be incorrect. The mean sidereal year is, according to Guillemin
365 days 6 hours 9 min. and 10.75 secs. = 365.25638 days,
according to Sewell and Dikshit
365 days 6 hours 9 min. and 9.29 secs. = 365.25635 days.
