Mahabharata 2.11.28

संवत्सराः पञ्चयुगमहोरात्राश्चतुर्विधाःकालचक्रं च यद्दिव्यं नित्यमक्षयमव्ययम्

saṃvatsarāḥ pañcayugamahorātrāścaturvidhāḥkālacakraṃ ca yaddivyaṃ nityamakṣayamavyayam

Our plain-language meaning of this verse is waiting for scholar review.