Śrāddha-prayoga: Niyama, Brāhmaṇa-parīkṣā, Kutapa-kāla, Tithi-nyāya, and Vaiṣṇava-phala
क्षयाहस्य तिथिर्या तु ह्यपराह्णद्वये यदि । पूर्वा क्षये तु कर्त्तव्या वृद्वौ कार्या तथोत्तरा ॥ २७ ॥
kṣayāhasya tithiryā tu hyaparāhṇadvaye yadi | pūrvā kṣaye tu karttavyā vṛdvau kāryā tathottarā || 27 ||
إذا وقع في يوم نقصان التِّثي (kṣaya) أن امتدّ التِّثي المعني عبر فترتي ما بعد الظهر كلتيهما، فحينئذٍ في حالة النقصان تُؤدَّى المراسم على التِّثي الأسبق؛ أمّا في حالة زيادة التِّثي (vṛddhi) فتُؤدَّى على التِّثي اللاحق.
Sanatkumara (teaching Narada the technical rules of tithi and ritual timing)
Vrata: none
Primary Rasa: shanta
Secondary Rasa: none
It protects the integrity (śuddhi) of vrata and pūjā by teaching correct tithi-nirṇaya, ensuring devotion is offered at the scripturally intended time rather than by guesswork.
Bhakti is expressed through disciplined observance; by aligning worship with the correct tithi (even during kṣaya/vṛddhi anomalies), the devotee’s intention and practice remain faithful to dharma.
Vedāṅga Jyotiṣa—specifically, the rule for deciding whether the earlier or later tithi governs an observance when a tithi is lost (kṣaya) or extended (vṛddhi), using aparāhṇa as the deciding window.