अधोलोकवर्णनम् (Adholoka-varṇana) — Description of the Lower Worlds and Cosmographic Measures
ऋतवस्त्रिंशतः सौरादयनानि दशैव तु / पञ्च च त्रिशतं चापि षष्टिवर्षं च भास्करम्
ṛtavastriṃśataḥ saurādayanāni daśaiva tu / pañca ca triśataṃ cāpi ṣaṣṭivarṣaṃ ca bhāskaram
In the solar reckoning, the ṛtus are thirty, and the ayanas are only ten. And for Bhāskara there are also said to be three hundred and five, and a cycle of sixty years.