Narada Purana — Purva Bhaga, Shloka 166
Jyotiṣa-śāstra Saṅgraha: Threefold Division, Gaṇita Methods, Muhūrta, and Planetary Reckoning
कालांशास्तैरूनयुक्ते रवौ ह्यस्तोदयौ विधोः । दृष्ट्वा ह्यादौ खेटबिंबं दृगौञ्च्ये लंबमीक्ष्य च ॥ १६६ ॥
kālāṃśāstairūnayukte ravau hyastodayau vidhoḥ | dṛṣṭvā hyādau kheṭabiṃbaṃ dṛgauñcye laṃbamīkṣya ca || 166 ||
太陽の時分（kālāṃśa）を減加によって正しく調整したなら、月の没と出を定めるべし。まず天体／月の円盤を視認し、さらに両眼の視線を合わせて垂線（lamba）を観察せよ。
Sanatkumara (in dialogue instruction to Narada on technical procedure)
Vrata: none
Primary Rasa: shanta
Secondary Rasa: adbhuta
FAQs
It treats disciplined observation and correct time‑reckoning (kāla-gananā) as part of dharmic order, showing that accurate knowledge of time supports right ritual timing and a life aligned with cosmic law.
Indirectly: by emphasizing correct determination of lunar timings, it supports proper observance of vows and worship schedules (often lunar-based), which strengthens steady devotional practice.
Vedāṅga Jyotiṣa—using kālāṃśa corrections and direct sighting of the luminary’s disc, along with vertical (laṃba) alignment, to determine the Moon’s rising and setting.