every now and

(every) now and again

Occasionally; sometimes. I don't travel often, but every now and again I just need to get away from the city. My mom has sweets now and again but mostly eats only healthy foods.
See also: again, and, now

(every) now and then

Occasionally; sometimes. Josh does stop by the store every now and then, but I haven't seen him lately. I don't eat a lot of sweets, but every now and then I just need a piece of chocolate cake.
See also: and, now
Farlex Dictionary of Idioms.

every now and

then/again
From time to time; occasionally.
See also: and, every, now
American Heritage® Dictionary of the English Language, Fifth Edition.
See also:
  • now and
  • now and again
  • now and again/then
  • (every) now and again
  • once and again
  • we must do this again (sometime)
  • over and over
  • over and over (again)
  • Let's do this again
  • let's do this again (sometime)