Page:The Burmese & Arakanese calendars (IA burmesearakanese00irwiiala).pdf/31

the Surya Siddhanta ratio of the length of a day to the length of a didi. (Para. 34). The fraction ${\frac {R}{25}}$ represents the 0.000004731 day, by which a Thandeikta mean lunation exceeds a Makaranta mean lunation. (See para. 39). The constant 176/692 day = 15 nayi, 15 bizana and 45 kaya, the time which elapsed from the moment of mean new moon to midnight of Tabaung Lagwè 1099 B. E. By Makaranta the kaya is the quotient of

${\frac {11H+650}{692}}$

the constant 650/692 day being = 55 nayi, 28 bizana and 35.5 kaya, the time which elapsed from the moment of mean new moon to midnight of Tabaung Lagwè 3738 Kali Yug. By the second Makaranta method the constant is 48/692.

60. Haragon + kaya = total didi. Didi divided by 30 gives quotient Sandra Matha, and remainder yet lun or epact at midnight of solar new year's day expressed in whole didi, the fraction of the epact being ${\frac {W}{692}}$.

61. Thandeikta rules for hnit-bo end here. Makaranta adds the following:— ${\frac {7L.M.}{235}}$ gives quotient adimath and remainder adimath thetha.

$L.M.-Ad=S.M.$

Divide solar months by 12. The quotient is the year or Ratha with which the calculations commenced. If there is no remainder the Ata Ne or Thingyan Tet falls in Tagu. If the remainder is 1 it falls in Kason. This remainder is the La lun.

62. The reason why this rule is not in Thandeikta is evident. The ratio 7/235 is the ratio of the Metonic cycle, which Thandeikta does not follow. It is the error of this ratio with reference to the Burmese solar year that causes Ata Ne to fall in Kason instead of Tagu. If the adimath were always adjusted in harmony with the solar year there would be no la lun.

63. If Thandeikta hnit-bo were calculated from Poppasaw's epoch, without cutting off 1100 years, the constant for the haragon would be 442 instead of 373. The added 69 kyammat consist of two items, 25 and 44. 25 represents the accumulated error of 1 kaya and 24 anukaya per year during 4839 years, from the beginning of the Kali Yug to 1100 B. E. We have seen (para. 55) that the error amounts to one kyammat in 193 years. 193 × 25 = 4825. The 44 kyammat represent the difference between Amarapura time and Lanka time which is used in Hindu calculations.

64. The following table of Thandeikta hnit-bo is copied from the Thandeikta Calendar for forty years, published by Saya Wizaya of Mandalay.