Srimad-Bhagavatam: Canto 12 - Chapter 1 - Verse 1
Sanskrit:
श्रीशुक उवाचकालस्ते परमाण्वादिर्द्विपरार्धावधिर्नृप ।कथितो युगमानं च शृणु कल्पलयावपि ॥ १ ॥
ITRANS:
śrī-śuka uvācakālas te paramāṇv-ādirdvi-parārdhāvadhir nṛpakathito yuga-mānaṁ caśṛṇu kalpa-layāv api
Translation:
Śukadeva Gosvāmī 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 Brahmā. I have also discussed the measurement of the different millennia of universal history. Now hear about the time of Brahmā’s day and the process of annihilation.