Shatapatha Brahmana 6.6.1.20

6.6.1.20

agnaye vaiśvānarāya svāheti | saṃvatsaro vā agnirvaiśvānaraḥ saṃvatsaro vā etadagre karmākarottamevaitadetasmai karmaṇe prayuṅkte

'To Agni Vaisvânara, hail!'--Agni Vaisvânara, doubtless, is the year; and the year, indeed, of old performed this rite; and he now makes use thereof for this rite.