Vishnupurana 3.14.3

3.14.3

māsi māsy asite pakṣe pañcadaśyāṃ nareśvara
tathāṣṭakāsu kurvīta kāmyān kālāñ chṛṇuṣva me //

AURVA proceeded.--"Let the devout performer of an ancestral oblation propitiate Brahmá, Indra, Rudra, the Áświns, the sun, fire, the Vasus, the winds, the Viśwadevas, the sages, birds, men, animals, reptiles, progenitors, and all existent things, by offering adoration to them monthly, on the fifteenth day of the moon's wane (or dark fortnight), or on the eighth day of the same period in certain months, or at particular seasons, as I will explain.