So for the 2nd day in a row cynder has waited until i have gotten home from work to go pee in the litter box. I feel this isn't healthy as holding it is not good. Is this normal or should I be concerned, we are talking like 7-8 hrs or longer before he will pee, and if its not normal how do I rectify this so he will go when we are out of the house for long periods of time.