I think the general consensus is about a month. People do this to train the chipmunk that it's aviary is it's home and so it should return to it to sleep. Pet owners have often described how difficult it can be to get them back in the aviary when they've needed to.
When I got my first chipmunk he was out the next day, I couldn't wait. He spent most of his time out on free range in the end, and because he could jump on me anytime he got very tame. I have found that a chipmunk which is used to being out on free range can really kick up a fuss when put back in to an aviary. Bitting and pulling at the mesh, even sulking. But you just have to be firm and ignore all their playing up, they will eventually occupy themselves or have a short sleep.