Tithi-Nirṇaya for Vratas: Ekādaśī Rules, Saṅkrānti Punya-kāla, Eclipse Observances, and Prāyaścitta
परेद्युर्विबुधश्रेष्टैः कुहूर्ग्राह्या पराह्णगा । मध्याह्नद्वितये व्यात्पा ह्यमावास्या तिथिर्यदि ॥ ३४ ॥
paredyurvibudhaśreṣṭaiḥ kuhūrgrāhyā parāhṇagā | madhyāhnadvitaye vyātpā hyamāvāsyā tithiryadi || 34 ||
O best of the wise, if the Amāvāsyā tithi (new-moon day) extends into the second midday period, then the Kuhū tithi should be observed on the previous day, taking the afternoon (parāhṇa) as its proper time.
Sanatkumara (in dialogue with Narada)
Vrata: none
Primary Rasa: shanta
Secondary Rasa: adbhuta
It emphasizes dharmic precision: sacred observances should follow correct tithi and time (kāla), because the fruit of a rite is tied to proper calendrical determination.
While technical, it supports bhakti-based vows by teaching when to perform them correctly; accurate timing protects the integrity of devotional observances offered to the deities.
Vedāṅga Jyotiṣa (Vedic calendrics/astronomy): it gives a rule for assigning the Kuhū observance based on Amāvāsyā’s extension across midday (vyāpti) and the parāhṇa criterion.