Brahma's one day means

Expressions researched:
"Brahma's one day means"

Srimad-Bhagavatam Lectures

So Brahmā's one day means one thousand times of the yugas.

Lecture on SB 1.3.15 -- Los Angeles, September 20, 1972:

So here is history also. This Vedic history is not that for one thousand years or two thousand years. No, not like that. One period. One millennium, Brahmā's one day, it is millions and millions of years. So just like there is night after day, day after night, similarly, the Brahmā's day, Brahmā's night, that is calculated. And one Brahmā's day. You know, that is described in the Bhagavad-gītā. Sahasra-yuga-paryantam ahar yad brahmaṇo viduḥ (BG 8.17). So Brahmā's one day means one thousand times of the yugas. The yugas means the Satya-yuga, Kali-yuga, and..., Tretā-yuga, Dvāpara-yuga, and Kali-yuga. So Satya-yuga's duration is about 1800,000's of years. The next, Tretā-yuga, duration about 1200,000's of years. And then Dvāpara-yuga, 800,000's of years, solar years.