Book of Indian Eras, with Tables for Calculating Indian Dates c32.9

c32.9

As the luni-solar year begins with the new moon immediately preceding the 1st of the solar Vaisâkh, the first step to be determined is the number of days by which the one precedes the other. For this purpose the beginning of the solar year has to be fixed, as already shown in the account of the Saura-Mâna, using the Solar Ahargana of the Surya Siddhânta for the North Indian dates and Aryabhatta’s Solar Ahargana for South Indian dates. The next step is to find the number of days of the luni-solar Ahargana in the given period, and to deduct this total from the number of days of the Solar Ahargana already found. The remainder is to be reduced by continued subtraction of whole lunations, until the last remainder is less than one lunation. Then that last remainder shows the exact number of days by which the new moon precedes the 1st day of the Solar Vaisâkh.