पृष्ठम्:आर्यभटीयम्.djvu/38

χΣΣνiii AR YABHATTYA elapsed, as the quotient. The remainder (of the division), when divided by 30, yields the civil months elapsed, as the quotient. The remainder gives the civil days elapsed of the current civil month. The lord of the first day of the year is called 'the lord of the year' and the lord of the first day of the month is called 'the lord of the month' ... Here, the number of civil years elapsed when multiplied by 3, then increased by 1, and then divided by 7, the remainder counted from Sunday gives the lord of the current year. The number of civil months elapsed when multiplied by 2, increased by 1, and then divided by 7, the remaining days counted from the lord of the current year give the lord of the current month.' The number 13, 17,416 which Suryadeva subtracts in the above rule is of special significance. This closely agrees with the teaching of Varahamihira in his Paica-siddhantika, i. 17. According to Varahamihira, a civil year started 13, 14,896 days after the commencement of Kaliyuga. The difference of the two epochs is 2520 days, i.e., exactly 7 civil years. Thus, according to Varahamihira, a civil year started 35 days before Aryabhata was 23 years old; and according to Suryadeva, a civil year started exactly 7 civil years thereafter. We do not know to which school the above teaching actually belongs. It certainly does not conform to the teaching of Aryabhata nor to the teaching of Brahmagupta; (see Prthudaka's commentary on the Khandakhadhyaka, i. 32, and Bhattotala's commentary on the same work, i. 25). There are certain astronomers who take the lord of the first day of the bright half of Caitra as the lord of the year. But this view is against the teaching of the Brahma school. Prthudaka says : "Those who take the lord of the first day of the light half of Caitra as the lord of the year, do not understand the Brahma-siddhanta. They have explained the Brahma-siddhanta incorrectly; for the lord of the year occurs after every 360 days commencing from the beginning of the Kalpa.” 16. Solstitial motion in the School of Suryadeva Sūryadeva states a correction due to solstitial motion and ascribes it to tradition. He says: