Jyotiṣa-śāstra Saṅgraha: Threefold Division, Gaṇita Methods, Muhūrta, and Planetary Reckoning
ग्रासेन स्वाहतेच्छाद्यमानामे स्युर्विशोपकाः । पूर्णांतं मध्यमत्र स्याद्दर्शांतेंजं त्रिभोनकम् ॥ १५८ ॥
grāsena svāhatecchādyamānāme syurviśopakāḥ | pūrṇāṃtaṃ madhyamatra syāddarśāṃteṃjaṃ tribhonakam || 158 ||
When the Moon’s portions (kalā) are covered by the Moon’s own ‘bite’ during an eclipse, they are called viśopakāḥ. In this reckoning, the ‘end of fullness’ is taken as the midpoint, and at the end of the fortnight (darśānta) the ‘unborn’ (aja) is declared to be threefold (tribhonaka).
Sanatkumara (teaching Narada in a technical dharma/observance context)
Vrata: none
Primary Rasa: adbhuta
Secondary Rasa: shanta
It links spiritual discipline with precise time-knowledge: understanding lunar transitions and eclipse-conditions is presented as part of dharmic order, supporting correct observance and inner steadiness.
Indirectly: by emphasizing correct ritual timing and clarity about lunar states, it supports orderly worship and vrata-practice, which in the Narada Purana are often framed as aids to steady Vishnu-bhakti.
Vedāṅga Jyotiṣa (astronomical/astrological reckoning): technical naming of obscuration during eclipse, and rules about ‘middle’ and ‘end’ points tied to pūrṇānta and darśānta calculations.