76. Hence the rule. When the awaman of Second Wazo Labyi is less than in the last preceding watat year Nayon has 29 days. When the awaman is greater than in the last preceding watat year Nayon has 30 days.
77. The day of the week on which the Labyi of Second Wazo falls in any watat year may be deduced from the last preceding watat year by dividing the increase of the haragon by 7. The result may be expressed thus:—
| Interval, years. |
Days in Nayon. |
Increase of haragon. |
Increase of week day. |
| 2 | 29 | 738 | 3 |
| 2 | 30 | 739 | 4 |
| 3 | 29 | 1092 | 0 |
| 3 | 30 | 1093 | 1 |
78. From the 1st of Tagu to the 15th of Second Wazo is in a wa-ngè-tat year 132 days, in a wa-gyi-tat year 133 days. Dividing by 7, we find that in a wa-ngè-tat year the 1st of Tagu falls one day later in the week than the Labyi of Second Wazo; in a wa-gyi-tat year they fall on the same day of the week. The Table in paragraph 77, therefore, gives the sequence of luni-solar New Year's Days from watat year to watat year, with this difference, in the case of New Year's Day the column "Days in Nayon" refers to the former watat year; in the case of Second Wazo it refers to the latter watat year.
79. Thandeikta does not give any clear and invariable rule for determining which years shall be watat, and the reason probably is that the Surya Siddhanta does not contemplate the Burma practice of placing the intercalary month always near the summer solstice. The Burmese sayas who framed the Thandeikta rules were thus thrown on their own wits for guidance, and the result is that several different tests are applied.
80. Dividing the number of days in one-fourth of a Maha Yug (394,479,457) by the number of adimath in the same period (398,334), we find that the average time from one intercalary month to the next should be 990 yet 19 nayi, 24 bizana, 1 kaya and 16.269 anukaya. Consequently it is laid down in Thandeikta that the period from one intercalary month to the next is 990 yet and 19 nayi.
81. To apply this principle, one method is to reduce the adimath thetha to days; another is to reduce the yet-lun to days. In each case the resulting days being subtracted from 990 days and 19 nayi, the difference is the number of days to run from solar new year's day before the adimath thetha amounts to a full month) or the yet-lun amounts to a full month, as the case may be. It is not expressly stated that an intercalary month should be inserted if the full
