Skandapurana 6.3.10.45

6.3.10.45

vaiṣṇavajñānamāsādya kecicchaivaṃ vrataṃ tathā .
ekarātraṃ dvirātraṃ ca kecitṣaṣṭhāhabhojanāḥ .. 10.45 ..

Having attained Vaiṣṇava knowledge, some undertook the Śaiva observance; / some fasted for one night, some for two nights, and some ate on every sixth day;