Viṣṇu Śṛṅkhalā Yoga 2221

Viṣṇu Śṛṅkhalā Yoga (Viṣṇu's Chain) occurs when Ekādaśī, Dvādaśī, and Śravaṇa Nakṣatra all overlap together on the first of Śravaṇa Dvādaśī's two candidate days, with Śravaṇa Nakṣatra directly touching both tithis; overlapping with Dvādaśī alone does not form this yoga.

This is not an annual occurrence: some years the alignment falls into place, other years it does not, since it depends on where Śravaṇa Nakṣatra happens to fall relative to that year's Ekādaśī-Dvādaśī boundary. When it occurs, the Śravaṇa Dvādaśī fast is observed on the first day; both Vaiṣṇavas and Smārtas fast on this day in place of a separate Ekādaśī fast.

Like most pañcāṅga determinations, this has been interpreted somewhat differently across sampradāyas over the centuries. Please follow the convention observed by your own family or tradition where it differs from what is shown here.