Tithi-Nirṇaya for Vratas: Ekādaśī Rules, Saṅkrānti Punya-kāla, Eclipse Observances, and Prāyaścitta
संपूर्णैकादशी शुद्धा द्वादश्यां नास्ति किंचन । द्वादशी च त्रयोदशयामस्ति तत्र कथं भवेत् ॥ ५१ ॥
saṃpūrṇaikādaśī śuddhā dvādaśyāṃ nāsti kiṃcana | dvādaśī ca trayodaśayāmasti tatra kathaṃ bhavet || 51 ||
إذا كانت الإكادشي تامّةً طاهرةً لا يمسّها شيء من الدوادشي، ومع ذلك كانت الدوادشي حاضرةً في يامٍ (جزء من الزمن) من يوم الترايودشي—فكيف يُحَدَّد حينئذٍ وجهُ العبادة الصحيح؟
Sanatkumara (in dialogue with Narada)
Vrata: Ekādaśī-vrata
Primary Rasa: shanta
Secondary Rasa: vicara (inquisitive/reflective)
It highlights that Ekādaśī-vrata is not merely fasting, but a dharmic discipline requiring purity of tithi; correct timing safeguards the sanctity of the vow offered to Viṣṇu.
By insisting on careful observance, it teaches that bhakti is expressed through attentive, rule-guided worship—honoring Viṣṇu with sincerity and precision rather than casual practice.
Vedāṅga Jyotiṣa (calendar/astronomical timekeeping): the verse raises a tithi-nirṇaya problem—when Dvādaśī is absent on its expected day but appears within Trayodaśī—prompting precise calculation for fasting and pāraṇa.