By resetting intonation, do you mean tuning the guitar? Although intonation does get set, it's normally not required more often than once unless you change string gauge.

Actual tuning with the pegs on the headstock happens frequently. I like to check tuning before I begin to play, then again after the guitar warms to my body heat. (Yeah it does.) If you don't own a tuner, get one and start using it. You owe it to your band. :D