Narada Purana — Purva Bhaga, Shloka 142
Jyotiṣa-śāstra Saṅgraha: Threefold Division, Gaṇita Methods, Muhūrta, and Planetary Reckoning
परमोपक्रमज्याप्त चापमेपादिगो रविः । कर्कादौ प्रोह्यचक्रार्द्धात्तुलादौ भार्द्धसंयुतात्त ॥ १४२ ॥
paramopakramajyāpta cāpamepādigo raviḥ | karkādau prohyacakrārddhāttulādau bhārddhasaṃyutātta || 142 ||
太陽（ラヴィ）が円の四分の一を進むとき、至高の upakrama-jyā の法によって得た弧を取って算定すべし。蟹宮およびそれに続く宮では半円から差し引き、天秤宮以後は「半」と結び合わせて（半円の規則により）取る。
Sanatkumara (teaching Narada in a technical Vedanga-style exposition)
Vrata: none
Primary Rasa: shanta
Secondary Rasa: adbhuta
FAQs
It shows that correct Dharma-practice depends on correct timekeeping; Jyotiṣa computations (like the Sun’s arc through zodiacal signs) support accurate calendars for vrata, yajña, and sacred observances.
Indirectly: Bhakti practices (fasts, pūjā timings, festival observances) require proper tithi and solar motion calculations; this verse supplies a technical rule that safeguards devotional discipline through right timing.
Vedāṅga Jyotiṣa—specifically, a quadrant/half-circle correction rule for solar arc computation across zodiacal halves (Cancer-side subtraction from 180°, Libra-side half-circle adjustment).