[Section on Light and Shadow] Laghumanasam | 15

Now, he explains the method for calculating the rising sign Udaya-lagnaThe point of the zodiac rising on the eastern horizon at a specific time. and with that the calculation of time NadikakaranaConverting the arc of the ecliptic into time units called Nadikas; 1 Nadika equals 24 minutes. using the phrase "By their own risings" original: "svodayairiti". The meaning is: the number of time units by which the Sun is increased to equal the rising sign is the duration in time. By using the rising times of the signs svodaya-vinadi and the desired time units, the Sun increased through the rule of three A mathematical proportion: if A gives B, what does C give? becomes the rising sign. When the Sun is at the equator and equals the rising sign, that constitutes the time.

This is what is being said: Add the precession of the equinoxes ayana-chalanaThe shifting of the celestial equator relative to the ecliptic over time. to the Sun at the given time. Multiply the remaining degrees to be traversed in the Sun's current sign by the rising time of that sign, divide by thirty, and subtract the resulting time units from the desired time. Add the remaining signs to the Sun-with-precession sayana-arka. Again, from the desired time units, subtract the rising times of as many signs as possible, starting from the sign immediately following the Sun's sign. Add those signs to the Sun. Then, multiply the remaining time units by thirty and divide by the rising time of the current sign. Take the resulting degrees and from the remainder, multiply by sixty and divide by those same rising times to get the minutes of arc. Add these degrees and minutes to that Sun and then subtract the precession of the equinoxes. That Sun becomes the rising sign.

For the calculation of time: Add the precession to both the Sun at the given time and the rising sign. Multiply the degrees to be traversed by the Sun by its sign's rising time and divide by thirty to get the time units. Then, multiply the degrees already traversed by the rising sign by its own rising time and divide by thirty. Add these time units to the previously calculated units. Also add the rising times of the signs situated between the Sun and the rising sign. These time units represent the time elapsed since sunrise.

At night, one should add six signs to the Sun-with-precession and calculate everything by treating the time elapsed since sunset as the elapsed time. If the time units to be traversed cannot be subtracted from the desired time, then multiply the desired time by thirty, divide by the sign's rising time, and add the resulting degrees and minutes to the Sun-with-precession, then subtract the precession. That becomes the rising sign. In the calculation of time, if the rising sign and the Sun are in the same zodiac sign, the time units are obtained simply from the degrees of difference between them. // 3 //

He explains the calculation of the length of the day and the zenith distance nata with the word "Inversely" original: "vyastam". Multiply the sine of the Sun-with-precession by the "arrow-multiplier" A specific constant used in these sine-table calculations. to find the ascensional difference chara-vinadiThe difference between the time of rising of a sign at the equator and at a specific latitude.. Convert these to time units by dividing by sixty and apply them inversely to "Sky-Fire" A Sanskrit numerical code (Bhutasankhya) where 'Sky' = 0 and 'Fire' = 3, meaning 30., i.e., thirty time units. If the Sun-with-precession is in the signs starting with Aries, add them...

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1. Or: "Again, from the remaining time units..."

2. Or: "Rising times..."

3. Or: "Minutes seen..."