I generally stay on my calling stands anywhere from 30-45 minutes. If I get a response in one out of 4 stands I feel I have done well. Night hunting is not permitted for coyotes where I live, so all my calling is in the early AM or at dusk. I usually stop calling around 10AM unless a storm is moving in, then I will keep at it as the predators are out hunting before the storm. Be sure to watch the down wind approach, and stay still and camo'ed up. A cover scent is a good idea too, cause coyotes have noses second to none.