Ācāra-Nirṇaya: Varṇa-Āśrama Dharma, Śauca, Snāna, Sandhyā, Japa, Tarpaṇa, and Gṛhastha-Dinacaryā
अहोरात्रस्य यः सन्धिः सा सन्ध्या भवतीति ह / द्विनाडिका भवेत्सन्ध्या यावद्भवति दर्शनम्
ahorātrasya yaḥ sandhiḥ sā sandhyā bhavatīti ha / dvināḍikā bhavetsandhyā yāvadbhavati darśanam
The junction of day and night is indeed called “Sandhyā”. Sandhyā lasts for two nāḍikās—so long as there remains visibility (of the sun’s presence).
Lord Vishnu (in dialogue teaching Garuda/Vinata-putra)
Concept: Dharma requires correct kāla (timing); Sandhyā is a measurable ritual interval.
Vedantic Theme: Kāla as a governing principle of karma; right action aligned with time supports inner purity (antaḥkaraṇa-śuddhi).
Application: Observe Sandhyā within the defined window (approx. two nāḍikās); plan daily schedule around sunrise/sunset visibility rather than convenience.
Primary Rasa: shanta
Secondary Rasa: adbhuta
Type: temporal-liminal
Related Themes: Garuda Purana 1.213.62 (consequence of omission); Garuda Purana 1.213.64 (post-rite homa instruction)
This verse defines sandhyā as the sacred transition between day and night and fixes its ritual window, supporting disciplined daily worship as a dharmic practice.
Sandhyā is stated to be two nāḍikās, i.e., a traditional two-unit time window around the day–night junction, lasting as long as visibility remains.
Treat sunrise/sunset as disciplined prayer windows: keep a consistent routine for meditation, japa, or sandhyā-vandana near the day–night transition rather than delaying it arbitrarily.