Shatapatha Brahmana 10.5.4.10

10.5.4.10

saṃvatsaro ha tvevaiṣo'gniścitaḥ tasya rātraya eva pariśritastāḥ ṣaṣṭiśca trīṇi ca śatāni bhavanti ṣaṣṭiśca ha vai trīṇi ca śatāni saṃvatsarasya rātrayo'hāni yajuṣmatya iṣṭakāstāḥ ṣaṣṭiścaiva trīṇi ca śatāni bhavanti ṣaṣṭiśca ha vai trīṇi ca śatāni saṃvatsarasyāhānyatha yā amūḥ ṣaṭtriṃśadiṣṭakā atiyanti yaḥ sa trayodaśo māsa ātmārdhamāsāśca te māsāśca caturviṃśatirardhamāsā dvādaśa māsā atha yadantarāhorātre tatsūdadohā atha yadahorātreṣvannaṃ tatpurīṣaṃ tā āhutayastāḥ samidho'tha yadahorātrāṇītyākhyāyate tallokampṛṇā tadvā etatsarvamahorātrāṇītyevākhyāyate tatsarvo'gnirlo

But, indeed, that Fire-altar also is the Year,--the nights are its enclosing-stones, and there are three hundred and sixty of these, because there are three hundred and sixty nights in the year; and the days are its Yagushmatî bricks, for there are three hundred and sixty of these, and three hundred and sixty days in the year; and those thirty-six bricks which are over are the thirteenth month, the body (of the year and the altar), the half-months and months,--(there being) twenty-four half-months, and twelve months. And what there is between day and night that is the Sûdadohas; and what food there is in the days and nights is the earth-fillings, the oblations, and the fire-logs; and what is called 'days and nights' that constitutes the space-filling (brick):--thus this comes to make up the whole Agni, and the whole Agni comes to be the space-filler; and, verily, whosoever knows this, thus comes to be that whole (Agni) who is the space-filler.