I'm convinced that part of any good time management program should include scheduling activities in a way that facilitates the avoidance of negative behavior.
There are times of the day when we are most prone to negative actions, such as watching mindless television programs, overeating, gossiping, etc. Look at your schedule and you'll probably spot your vulnerable zones. We do not consciously book negative actions. They slip into the unbooked territory; those times when we have let down our guard.
Those are the hours that need to be filled with more productive activities. Doing so gives us the dual benefit of the positive action itself and the avoidance of the negative action.
Those open hours need to be filled in consciously and productively or they will inadvertently be devoted to actions that can be truly harmful.