Depends on the snake. Nippier youngsters we try to handle just a few minutes each day, just long enough to spot-clean and change water, so they learn that "godzilla" won't hurt them. Adults and more tolerant youngsters maybe 1-2 times a week.
They don't get messed with at all the day after feeding without a good reason, such as changing water b/c the snake defecated in it, and even then the most we would do is shift them to another part of the enclosure.