Thus enters the term "Range Nazi". Nothing wrong with extending the customers' time if it doesn't affect any others waiting. Most people enjoy a little slack on things like this....couple extra revs on the ferris wheel, few more minutes on the horse, couple more laps in the go-kart, etc. If there's nobody waiting, WTFN?
Anyway, who can tolerate two full hours of standing in a stall and blasting away, without a break or taking the muffs off? I sure couldn't anyway.