I agree. Except about the duration. When we used to do it, we'd usually stay up all night skateboarding & things like that. I'd say you should have at least 12 to 24 hours free where you don't have to interact with any authority figures or people who could give you bad vibes. The essential thing is to be with good people, and to have a safe place to go to where you can chill out & relax if need be. The best times I had were out in a national park or camping or something... where we could get away from things like cars & people & noise.