The Exposition of the Dvādaśī Vow for the Twelve Months
Dvādaśī-vrata-nirṇaya and Mahā-dvādaśī Lakṣaṇas
श्रवणर्क्षयुतायां च द्वादश्यां भाद्रशुक्लके । ऊर्ज्जे सितायां द्वादश्यामंत्यभे च व्रतद्वयम् ॥ ११५ ॥
śravaṇarkṣayutāyāṃ ca dvādaśyāṃ bhādraśuklake | ūrjje sitāyāṃ dvādaśyāmaṃtyabhe ca vratadvayam || 115 ||
Bila pada paruh terang Bhādrapada, Dvādaśī bersatu dengan nakṣatra Śravaṇa, dan bila pada paruh terang Ūrja (Āśvina) Dvādaśī jatuh pada nakṣatra terakhir, Revatī, maka dua vrata hendaknya dijalankan secara terpisah.
Narada
Vrata: Dvādaśī-vrata (instruction: vratadvayam—two vows—to be observed on specified yogas)
Primary Rasa: shanta
Secondary Rasa: none
It teaches that vrata-results depend on precise sacred timing—tithi (Dvādaśī) harmonized with nakṣatra (Śravaṇa/Revatī)—showing Dharma as both devotion and disciplined alignment with cosmic order.
By prescribing specific Dvādaśī-based vratas, it directs devotion into regulated worship and fasting practices traditionally offered to Viṣṇu, where correct observance becomes an act of bhakti.
Jyotiṣa (Vedāṅga astrology): it uses the calendrical science of tithi (Dvādaśī), pakṣa (bright fortnight), lunar months (Bhādrapada/Ūrja), and nakṣatra (Śravaṇa/Revatī) to determine ritual timing.