from time to time
Definitions
Occasionally; now and then.
At irregular intervals; not frequently.
Examples
I like to visit my old hometown from time to time to see how much it has changed.
Even though they live in different cities, they still call each other from time to time.
Synonyms
occasionally now and then at intervals periodically sometimes every so often sporadically
Antonyms
always constantly frequently regularly continuously perpetually incessantly