With the Commentary of Parameshvara - [Chapter on the Three Problems]

For the signs beginning with Libra The autumnal equinox, one should subtract. That results in the length of the day. By subtracting the length of the day from sixty A full day-night cycle is 60 ghatikas or 24 hours, the remainder is the length of the night. The "noon-offset" ghatikas are those elapsed before or after midday. He explains the method for calculating this: "the difference between half-day and elapsed time." This means the difference between the measure of half the day and the ghatikas already passed since sunrise is the "noon-offset" (Nata). || 4 ||

Multiply the specific ascensional difference by five, adjust by the equinoctial shadow,
and from the primary sine of the ascensional difference, divided by twice the day,
the midday shadow is found. || 5 ||

Now he describes the method for finding the midday shadow, which serves as the basis for finding the shadow at any desired time: "Multiply by five," etc. At the desired time, one should calculate the vinadis units of time of the ascensional difference for the tropical sun, multiply by five, halve it, and divide by the inches of the equinoctial shadow Palabha The shadow of a 12-digit gnomon at noon on the equinox of one's own location. The result should be applied to the primary sine of the ascensional difference.

When the sun is in the signs beginning with Aries, one should subtract. When the sun is in the signs beginning with Libra, one should add. This adjusted primary sine should be divided by "twice the day"—that is, the length of the day in ghatikas minus ten. The result is the length of the shadow in inches Angulas at midday. From the remainder, multiplied by sixty and divided by twice the day, the fractional inches Vyangu-las are obtained. If the result from the equinoctial shadow (which is subtractive) is greater than the sine of the day's motion, then subtract the primary sine from it; the remainder divided by twice the day gives the midday shadow. This midday shadow, along with its fractional parts, should be kept aside. || 5 ||

From the product of the "reduced day" and nine, divided by the square of the noon-offset;
adding a hundredth of the "reduced day," that is the Multiplier;
that minus one is the Divisor. || 6 ||

He explains the calculation of the shadow at a desired time: "Reduced day," etc. The length of the day in ghatikas minus ten is called the "reduced day" Vidig-dina. Multiply the "reduced day" ghatikas by nine and divide by the square of the noon-offset ghatikas at that time. Add the resulting fraction to one-hundredth of the "reduced day" ghatikas. This is the Multiplier Gunaka. The ninth part of the "reduced day" is always a fraction. Therefore, that fraction is added to the fraction of the "noon-offset square" portion. This is the Multiplier. "Minus one is the Divisor"—this means the Multiplier minus one is the Divisor Haraka. Having calculated the Multiplier and Divisor, they should be kept together.

However, near sunrise, because the Multiplier is less than one, a Divisor cannot be formed. Therefore, a "corrected Multiplier" must be calculated there. The method for that: at sunrise, calculate the Multiplier using the rule "From the product of the reduced day..." etc., and then add or subtract the difference between that Multiplier and the number one to the desired Multiplier. If the Multiplier is greater than one, add; if less than one, subtract. That becomes the "corrected Multiplier" Sphuta-guna. As someone else has said:

1. K. "of the two ghatikas" 2. K. "of the primary sine" 3. K. "portion of the square" 4. K. "produced from the time" 5. K. "hundredth of the day"