सूर्यरथ-कालचक्र-आयनविभागः, संध्योपासनम्, देवयान-पितृयानम्, विष्णुपद-गङ्गावतरणम्
उषा रात्रिः समाख्याता व्युष्टिश् चाप्य् उच्यते दिनम् प्रोच्यते च तथा संध्या उषाव्युष्ट्योर् यद् अन्तरम्
uṣā rātriḥ samākhyātā vyuṣṭiś cāpy ucyate dinam procyate ca tathā saṃdhyā uṣāvyuṣṭyor yad antaram
Night is designated as uṣā, and day is also called vyuṣṭi. The interval between uṣā and vyuṣṭi is spoken of as saṃdhyā, the sacred junction of time.
Sage Parāśara (in instruction to Maitreya)
Cosmic Hierarchy: Lokas
Concept: Time’s junction (saṃdhyā) between night (uṣā) and day (vyuṣṭi) is a sacred threshold suited for purification and remembrance.
Vedantic Theme: Dharma
Application: Treat dawn and dusk as non-negotiable anchors for japa, prayer, and mindful transition rather than hurried routine shifts.
Vishishtadvaita: Sacred time becomes a mode of approach to the personal Lord (Nārāyaṇa) through regulated devotion, integrating cosmic order with embodied practice.
Vishnu Form: Narayana
Bhakti Type: Shanta
This verse defines saṃdhyā as the interval between night (uṣā) and day (vyuṣṭi), highlighting it as a liminal, sacred turning-point in the daily cycle of cosmic order.
He explains time through precise naming: night is termed uṣā, day is termed vyuṣṭi, and the transitional interval between them is saṃdhyā—showing that cosmic time is understood through structured thresholds.
Even without naming Vishnu directly, the verse supports the Purāṇic view that orderly time-cycles are a manifestation of the Supreme Reality’s governance—Vishnu as the sustaining principle behind rhythm, law, and continuity in the cosmos.