We collect our eggs every day so they don't have to stay out in the heat for too long, but in the colder months we have gone on short vacations (up to a week) and returned to find all the eggs still okay.
I check for eggs everyday, morning and evening. I figure I already have to go out to open the door in the morning and close it at night, so why not check while I'm there. I have lots of hens prone to broodiness though, so I can leave any eggs in the nest boxes! Good luck.