Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 2 · Signs, Planets, Birth
जातकम् १
भगणांशैर्लब्धहीनास्तेषां कार्या विचक्षणैः ।पापस्यांशाः समग्रोना सौम्यस्यार्द्धविवर्जिताः ॥ १२५ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 55, verse 125.
Divide by the degrees of the full circle. The wise take the result away from those years. For a bad planet, take away the whole. For a good planet, take away half.
Simple meaning: The rising planet cuts the years by a share. A bad one cuts the whole, a good one half.
स्पष्टास्तेंशाः खषट्त्र्यासा गुणयित्वा स्वकैर्गणैः ।
Degree parts are turned into years and months by multiplication and division.
तच्छेषश्च त्रिगुणितः तेनैवाप्तं दिनानि च ।
The remainders are turned into days and smaller units.
हित्वा भाज्यंगभागादीन्कलीकृत्य खखाक्षिभिः ।
The rising sign's degrees are turned into minutes and divided to give years.