Shatapatha Brahmana 4.3.1.10

4.3.1.10

tau vā ṛtuneti ṣaṭ pracarataḥ | taddevā aharasṛjantartubhiriti catustadrātrimasṛjanta sa yaddhaitāvadevābhaviṣyadrātrirhaivābhaviṣyanna vyayavatsyat

Six times they perform with, 'With the season'--thereby the gods created the day; and four times with, 'With the seasons'--thereby they created the night. And, assuredly, were only this much (used), there would be nothing but night: it would never pass away.