# The Burmese & Arakanese Calendars/Chapter 1

THE BURMESE & ARAKANESE CALENDARS.
1. Of natural measures of time, denoted by revolutions and rotations of the heavenly bodies, the best-known and most important are the year, the lunation or synodic month, and the day. The principal artificial measures are the solar month (one-twelfth of a year}, the week, the hour, the minute, and the second.
2. For a description of the different measures of the year and month (tropical, sidereal and anomalistic years, synodic, sidereal, anomalistic, tropical and nodical months) the reader is referred to text books of astronomy. Such a description would be too lengthy to insert here.
3. The tropical year, lunation and day vary slightly in length, but none of them is ever an even multiple or sub-multiple of another. Therefore the problem of constructing a calendar to measure time by these three units is a very complex one. In Europe. Julius Cæsar simplified it enormously by abandoning the lunation altogether, and dividing the year into twelve artificial solar months without any remainder. This was not done in Asia, where lunations are still used.
4. Other methods of simplifying the problem are—
(a) To reckon by mean or average years and lunations, instead of by the actual revolutions of the earth and moon, the periods of which vary slightly.
(b) To postpone fractions of a day, and reckon each lunar month and each year as commencing at midnight, the accumulated fractions being added to the month or year periodically when they amount to one day.
(c) To add the accumulated fractions of months and days not exactly when they amount to integers, but at regularly recurring intervals, on the principle of averages and by the aid of cycles which are more or less accurate common multiples of days, lunations and years.
These methods have been adopted to varying extents at different times and in different parts of Asia, as will be seen later.
​5. The Burmese calendar is essentially a Buddhist one, but the methods of computing it are derived from Hindu books. A few words about the Hindu calendar are therefore necessary.
6. In paragraph 17 of "The Indian Calendar," by Sewell and Dikshit, is a list of some of the best-known Hindu works on astronomy. The length of the year is differently estimated in different works. The principal ones which seem to have been used in Burma are the Original Surya Siddhanta and the present Surya Siddhanta. The length of the year as given in these two is respectively:—
7. Sewell and Dikshit show (at paragraphs 47 and 52) that the Hindus formerly reckoned by mean months and years, but at present by apparent months, while both mean and apparent years are used indifferent parts of India. The change from mean to apparent reckoning is supposed to have commenced about A. D. 1040, as it is enjoined in a passage in the Siddhanta Sekhara by the celebrated astronomer Sripati, written in or about that year.
8. The Hindus insert an intercalary month at any time of year, as soon as the accumulated fractions amount to one month. In Burma, as we shall see, this is not so. The intercalary month is always inserted at the same time of year, in Burma proper after the summer solstice, in Arakan after the vernal equinox.
9. Burmese astronomers use the Hindu Kali Yug, which commenced in 3102 B. C. (Sewell and Dikshit, page 16).
Gautama Buddha’s grandfather, King Einzana, is said to have started a new era in 691 B. C.
The Religious Era dates from 543 B. C., the year in which Gautama is supposed to have attained Nirvana.
In A. D. 78-9 King Thamondarit of Prome is said to have started another, identical with the Indian Saka era.
In A. D. 638-9 the era now in common use was started simultaneously, in Burma by King Poppasaw of Pagan and in Arakan by King Thareyarenu of Dinyawadi dynasty. The same era is current in Chittagong under the name of Magi-San. (Sewell and Dikshit, paragraph 71 and table III).
10. So far as I am aware, no record is extant of any calendars as actually observed either in Burma or in Arakan earlier than the year 1100 of Poppasaw’s era (A. D. 1738). Mr. Htoon Chan, B. A., B. L., of Akyab, in his book The Arakanese Calendar, published in 1905, gives the elements of the luni-solar calendar of Arakan for 2,000 years of the current era (A. D. 639 to 2638), but he states that these were compiled during the reign of King Na-ra-a-pa-ya ​(A. D. 1742 to 1761), and it is not clear whether the details given for earlier years represent what was actually observed or not.
11. The Arakanese follow the rules of Makaranta, in which fractions are reduced to their lowest terms, and very small remainders are neglected. Intercalary months are regulated by the Metonic cycle of 19 years, the use of which was propounded in the 10th book of Raja-Mathan, a Hindu astronomer.
12. The Makaranta is probably derived from the original Surya Siddhanta, because it defines the length of the year as 365 days, 15 nayi, 31 bizana 30 kaya (365 days, 6 hours, 12 minutes and 36 seconds), and because it uses mean reckoning. It is probable that the Burmese followed the same rules from Poppasaw's time down to 1100 B. E. (A. D. 1738).
13.The book which is now used in Burma is Thandeikta, the origin of which is involved in some obscurity. According to one account it was written about 1100 B. E., according to another about 1200. At any rate the change from Makaranta to Thandeikta reckoning was not effected all at once. From 1100 to 1200 the intercalary months are still regulated by the Metonic cycle, as in Arakan, but the intercalary days are not placed in the same years as in Arakan, and it is not clear by what rule they were fixed. During that century the growing discrepancy between the civil solar and luni-solar Years attracted attention. Much controversy ensued, the party of reform being led by a princess afterwards the chief Queen of King Mindon. The first departure from the rule of the Metonic cycle was made by putting an intercalary month in 1201 instead of in 1202, but the rules of Thandeikta do not appear to have been fully introduced untill 1215.
14. Thandeikta is based chiefly, if not entirely, on the present Surya Siddhanta, but applies its rules only to a limited extent. According to one account the present Surya Siddhanta was not known in Burma until one Bhavani Din, a learned pandit of Benares, brought it to Amarapura in 1148 B. E. (A. D. 1786), and about fifty years later it was translated into Burmese. Thandeikta does not adopt the system of apparent reckoning; mean years and mean months are still used. The practice of placing the intercalary month always next after Wazo and the intercalary day always at the end of Nayon, and only in a year which has an intercalary month, is still adhered to. But the new Surya Siddhanta was followed in small alterations of the length of the year and the month, and the Metonic cycle was abandoned, and intercalary months so fixed as to prevent further divergence between the solar and luni-solar years.