Revākhaṇḍa ascribed to the Vāyupurāṇa (RKV) 54.52

54.52

cāndrāyaṇaratāḥ kecit kecit pakṣopavāsinaḥ /
māsopavāsinaḥ kecit kecidṛtvantapāraṇāḥ //

some devoted to the cāndrāyaṇa penance, some fasting for a fortnight,
some fasting for a month, some breaking fast at the end of a season;