Srimad Bhagavatam Canto 12, Chapter 04, Text 38

SB 12.4.38

nityo naimittikas caiva
 tatha prakrtiko layah
atyantikas ca kathitah
 kalasya gatir idrsi
 
Translation: 
 
In this way the progress of time is described in terms of the four kinds of annihilation — continuous, occasional, elemental and final.
Srimad Bhagavatam Canto 12, Chapter 04, Text 37
Srimad Bhagavatam Canto 12, Chapter 04, Text 39