SB 12.4.1
sri-suka uvaca
kalas te paramanv-adir
dvi-parardhavadhir nrpa
kathito yuga-manam ca
srnu kalpa-layav api
Translation:
Sukadeva Gosvami said: My dear King, I have already described to you the measurements of time, beginning from the smallest fraction measured by the movement of a single atom up to the total life span of Lord Brahma. I have also discussed the measurement of the different millennia of universal history. Now hear about the time of Brahma’s day and the process of annihilation.