Mahabharata 1.3.64

1.3.64

ekāṃ nābhiṃ saptaśatā arāḥ śritāḥ pradhiṣvanyā viṃśatirarpitā arāḥ |
anemi cakraṃ parivartate'jaraṃ māyāśvinau samanakti carṣaṇī || 64 ||

"The year is but the nave of a wheel to which is attached seven hundred and twenty spokes representing as many days and nights. The circumference of this wheel represented by twelve months is without end. This wheel is full of delusions and knows no deterioration. It affects all creatures whether to this or of the other worlds. Ye Aswins, this wheel of time is set in motion by you!