Daily Reading: Caitanya Caritamrita page-91

CC Ādi 3.8

ekāttara catur-yuge eka manv-antara
caudda manv-antara brahmāra divasa bhitara

Translation: 

Seventy-one divya-yugas constitute one manv-antara. There are fourteen manv-antaras in one day of Brahmā.

Purport: 

A manv-antara is the period controlled by one Manu. The reign of fourteen Manus equals the length of one day (twelve hours) in the life of Brahmā, and the night of Brahmā is of the same duration. These calculations are given in the authentic astronomy book known as the Sūrya-siddhānta. An annotated Bengali translation of this book was compiled by the great professor of astronomy and mathematics Bimal Prasād Datta, later known as Bhaktisiddhānta Sarasvatī Gosvāmī, who was our merciful spiritual master. He was honored with the title Siddhānta Sarasvatī for translating the Sūrya-siddhānta, and the title Gosvāmī Mahārāja was added when he accepted sannyāsa, the renounced order of life.

CC Ādi 3.9

‘vaivasvata’-nāma ei saptama manv-antara
sātāiśa catur-yuga tāhāra antara

Translation: 

The present Manu, who is the seventh, is called Vaivasvata [the son of Vivasvān]. Twenty-seven divya-yugas [27 × 4,320,000 solar years] of his age have now passed.

Purport: 

The names of the fourteen Manus are as follows: (1) Svāyambhuva, (2) Svārociṣa, (3) Uttama, (4) Tāmasa, (5) Raivata, (6) Cākṣuṣa, (7) Vaivasvata, (8) Sāvarṇi, (9) Dakṣa-sāvarṇi, (10) Brahma-sāvarṇi, (11) Dharma-sāvarṇi, (12) Rudraputra (Rudra-sāvarṇi), (13) Raucya, or Deva-sāvarṇi, (14) and Bhautyaka, or Indra-sāvarṇi.