SB 12.3.17
yugani yuga-dharmams ca
manam pralaya-kalpayoh
kalasyesvara-rupasya
gatim visnor mahatmanah
Translation:
Please explain the different ages of universal history, the special qualities of each age, the duration of cosmic maintenance and destruction, and the movement of time, which is the direct representation of the Supreme Soul, the Personality of Godhead, Lord Visnu.