Small Manual of Astronomical Computation with the Commentary of Paramesvara

Again, placing it below, divide the bottom-most of those three quantities by sixty. Taking only the whole-number results, subtract them from the middle quantity. Divide that middle quantity by twenty; taking the whole-number results, set them aside somewhere. Subtract the remainder from the top-most quantity. To that quantity, add all the lunar days tithis starting from the first day of the bright fortnight of the month of Chaitra in the current year. Then, from that quantity, subtract three times the "Fixed Years" dhruvābda: a constant or epochal year-count used in the system and the elapsed seasons of the current year. That quantity is called the Day-Count Dyugaṇa: the total number of days elapsed from a fixed epoch. When that is divided by seven, the remainder indicates the day of the week starting from the "Fixed Day" dhruvavāsara. By adding or subtracting this Day-Count, the desired weekday is determined. However, if at the start of the year the triple-years cannot be subtracted, then one should subtract the quantity (including the Chaitra lunar days) from the triple-years minus the remainder of the years divided by thirty. In that case, the remainder is known as the Negative Day-Count Ṛṇadyugaṇa. Subtracting that from seven, the weekday is determined from the remainder. This occurs when the Fixed Year count is one or two. || 3 || 4 ||

|| 5 ||

Now he describes the calculation of the mean position of the Sun: "The Day-Count..." etc. Having placed the Day-Count for the desired day, and placing it again separately below, add ten times the Fixed Years to the lower one. Divide that by seventy original: "khāga", where kha=0 and aga=7, using the Katapayadi system. Subtract the resulting degrees from the upper quantity. Multiply the remainder by sixty and divide again by seventy; the resulting minutes liptā should be subtracted from the upper portion after converting one degree into minutes. Again, subtract eight times the Fixed Years from the upper quantity, and add minutes equal to one-eighth of the Fixed Years to the total minutes. The result will be the degrees. This means the degrees are in the upper position and the minutes are in the lower. Again and again, raising the upper degrees by twenty, add the "Fixed Constant" dhruva. That becomes the Mean Sun. If the eight-fold years cannot be subtracted, subtract the solar degrees and minutes from the eight-fold years, and subtract that remainder from the Fixed Constant. To that remainder, add the minutes from one-eighth of the years; that is the Mean Sun. In the case of a Negative Day-Count, subtract the Negative Day-Count from the ten-fold years; add the result of the division by seventy to the Negative Day-Count, add the eight-fold years to that as well, and then subtract that from the Fixed Constant. Add the minutes from one-eighth of the years to the remainder. That is the Sun. || 5 ||

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1. Variant: ...all the elapsed lunar days...

2. Variant: ...adding one to the Day-Count...

3. Variant: ...the Negative Day-Count...

4. Variant: ...the weekday is found as before. For counts of one, two, or three...

5. Variant: ...ten-fold years...

6. Variant: ...solar degrees...

7. Variant: ...minutes...

8. Variant: ...subtract from the upper portions...

9. Variant: ...they are. In the upper...

10. Variant: ...Again, the upper...

11. Variant: ...Mean Sun...

12. Variant: ...subtract the constants...