SB 8.13.36
rajams caturdasaitani
tri-kalanugatani te
proktany ebhir mitah kalpo
yuga-sahasra-paryayah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
O King, I have now described to you the fourteen Manus appearing in the past, present and future. The total duration of time ruled by these Manus is one thousand yuga cycles. This is called a kalpa, or one day of Lord Brahma.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Thus end the Bhaktivedanta purports of the Eighth Canto, Thirteenth Chapter, of the Srimad-Bhagavatam, entitled “Description of Future Manus.”