Śatapatha Brāhmaṇa ("of a hundred paths") 9.3.3.18

9.3.3.18

tadāhuḥ | kathamamasyaiṣā vamordhārā saṃvatsaramagnimāpnoti kathaṃ saṃvatsareṇāgninā sampadyata iti ṣaṣṭiśca ha vai trāṇi ca śatānyeṣā vasordhārātha ṣaḍatha pañcatriṃśattato yāni ṣaṣṭiśca trīṇi ca śatāni tāvanti saṃvatsarasyāhāni tatsaṃvatsarasyāhānyāpnotyatha yāni ṣṭ ṣaḍvā ṛtavastadṛtūnāṃ rātrīrāpnoti tadubhayāni saṃvatsarasyāhorātrāṇyāpnotyatha yāni pañcatriṃśatsa trayodaśo māsaḥ sa ātmā triṃśadātmā pratiṣṭhā dve prāṇā dve śira eva pañcatriṃśametāvānvai saṃvatsara evamu hāsyaiṣā vasordhārā saṃvatsaramagnimāpnotyevaṃ saṃvatsareṇāgninā sampadyata etāvatya u vai śāṇḍile 'gnau madhyato yajuṣmatya iṣṭakā upadhīyante 'gnayo haite pṛthagyadetā iṣṭakā evamu hāsyaite 'gnayaḥ pṛthagvasordhārayābhihutā bhavanti

As to this they say, 'How does this wealth-shower of his obtain (conformity with) the year, and Agni? how does it correspond to the year, to Agni?' Well, this shower of wealth consists of three hundred and sixty (libations), and of (other) six, and of thirty-five. Now, the three hundred and sixty which there are,--so many being the days in the year,--thereby it obtains the days of the year. And what six there are,--the seasons being six in number,--thereby it obtains the nights of the seasons: thus it obtains both the days and nights of the year. And what thirty-five there are, they are the (intercalary) thirteenth month, and that is the body,--the body (consists) of thirty (limbs), the feet of two, the breath of two (in-breathing and up-breathing), and the head is the thirty-fifth: so much is the year; and thus that shower of wealth of his obtains (conformity with) the year, and Agni; and thus it corresponds to the year, to Agni. And so many are the bricks with special formulas which are placed in the centre of a Sândila fire-altar; for these bricks indeed are the same as these different Agnis; and thus these Agnis of his come to have oblations offered to them separately by means of the shower of wealth.