Tithi-Nirṇaya for Vratas: Ekādaśī Rules, Saṅkrānti Punya-kāla, Eclipse Observances, and Prāyaścitta
प्रदोषव्यापिनी ग्राह्या त्वन्यथा निष्फलं भवेत् । अर्द्धरात्रादधो या तु नक्षत्रव्यापिनी तिथिः ॥ ११ ॥
pradoṣavyāpinī grāhyā tvanyathā niṣphalaṃ bhavet | arddharātrādadho yā tu nakṣatravyāpinī tithiḥ || 11 ||
Man soll die Tithi annehmen, die sich durch die Pradoṣa-Zeit erstreckt; andernfalls wird das Ritual fruchtlos. Doch die Tithi, die nach Mitternacht in den späteren Teil der Nacht hinab reicht und dabei das Nakṣatra umfasst, gilt als maßgeblich.
Sanatkumara (in dialogue instruction to Narada on observance rules)
Vrata: none
Primary Rasa: shanta
Secondary Rasa: bhayanaka
It teaches that devotion and ritual observance must be aligned with correct sacred time (kāla); if the tithi is wrongly chosen, the intended spiritual fruit of the vrata or pūjā is said to be lost.
Bhakti is expressed through disciplined observance; the verse emphasizes that sincere worship is supported by proper vrata-timing—showing that devotion is not only emotion but also careful adherence to dharma-based procedure.
Jyotiṣa (Vedāṅga astrology): selecting the operative tithi by its extension through pradoṣa and by its overlap with nakṣatra, including the rule referencing the post-midnight portion of the night.