Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 6 · Calendar, Muhurta Elements
कालमानं मुहूर्ताङ्गानि च
पर्ववास्तूपवासादि कृत्स्नं चांद्रेण गृह्यते ।गृह्यते गुरुमानेन प्रभवाद्यब्दलक्षणम् ॥ ११३ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 56, verse 113.
Parva (junction day) days, house-building, fasts and the like are all taken by the Moon's measure. The marks of the years, starting with Prabhava, are taken by Jupiter's measure.
Simple meaning: Fasts and house rites follow the Moon. The sixty-year names follow Jupiter.
तत्तन्मासैर्द्वादशभिस्तत्तदष्टौ भवेत्ततः ।
Twelve months of any kind make a year. Jupiter's average movement gives the sixty named years.
प्रभवो विभवः शुक्लः प्रमोदोऽथ प्रजापतिः ।
These are the first ten names of the sixty-year cycle.
ईश्वरो बहुधान्यश्च प्रमाथी विक्रमो वृषः ।
These are the next ten names of the sixty-year cycle.