Srimad-Bhagavatam: Canto 8 - Chapter 1 - Verse 11
अष्टमेऽन्तर आयाते सावर्णिर्भविता मनु: ।निर्मोकविरजस्काद्या: सावर्णितनया नृप ॥ ११ ॥
aṣṭame ’ntara āyātesāvarṇir bhavitā manuḥnirmoka-virajaskādyāḥsāvarṇi-tanayā nṛpa
O King, when the period of the eighth Manu arrives, Sāvarṇi will become the Manu. Nirmoka and Virajaska will be among his sons.
The present reign is that of Vaivasvata Manu. According to astronomical calculations, we are now in the twenty-eighth yuga of Vaivasvata Manu. Each Manu lives for seventy-one yugas, and fourteen such Manus rule in one day of Lord Brahmā. We are now in the period of Vaivasvata Manu, the seventh Manu, and the eighth Manu will come into existence after many millions of years. But Śukadeva Gosvāmī, having heard from authorities, foretells that the eighth Manu will be Sāvarṇi and that Nirmoka and Virajaska will be among his sons. Śāstra can foretell what will happen millions and millions of years in the future.