Matsyapurana 142.11

142.11

triṃśadyāni tu varṣāṇi divyo māsastu sa smṛtaḥ
mānuṣāṇāṃ śataṃ yacca divyā māsāstrayastu vai
tathaiva saha saṃkhyāto divya eṣa vidhiḥ smṛtaḥ //

Thirty years of men is one month of the Devas A century of men is 3 months and some days of the Devas 360 human years make one year of the Devas 3,030 human years make one year of the Sapt Ṛiṣis 9,000 human years make one year of Dhruva, called, Dhruva Samvatsara 36,000 human years make one thousand Divine years—11-17