Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 2 · Signs, Planets, Birth
जातकम् १
आयुरंशकलाभक्ताद्विंशत्याब्दा इनाहतम् ।शेषं द्विशतभक्तं स्युर्मासाः शेषा दिनादिकम् ॥ १३३ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 55, verse 133.
Divide the life degrees, in minutes, by 20 to get years. Multiply the remainder by 12 and divide by 200: months. The rest gives days and the like. (Our text is unclear here: it says twenty, where the months step divides by 200.)
Simple meaning: The lifespan in minutes is divided to give years, months and days.
लग्नायुरंशास्त्रिगुणा दिग्भक्ता स्युः समास्ततः ।
The rising sign's parts are turned into years and months.
सबलेंगेभतुल्याब्दैर्युतमायुर्भवेत्स्फुटम् ।
A strong rising sign adds years equal to its signs, and months from its degrees.
शेषा दिनादिकं योज्यं नैतत्पिंडनिसर्गयोः ।
The strongest among the rising sign, Sun and Moon has its period first.