I also agree with 3sons on location of the fish. Shallows close to a bay and across the mouth of the bay is the place to fish. I, too, have noticed that they turn on and off at odd times. What I notice most is there is no point to fishing for wipers after dark--they rarely bite. There is not point in fishing for them early in the morning--they rarely bite. They usually start to bite (as far as I have ever seen) at about 11:00 a.m. They bite about two hours, then quit. At about an hour before sunset--just when the sun is almost ready to drop below the horizon and until the last bit of daylight lingers they will bite hard. I've often thought of not bothering to get on the lake until 4 p.m. I'm pretty sure that I would do just as well fishing late in the day at this time of the year as I would if I fished all day. Spring is different. They still won't bite until about 11 a.m., but they will bit all day long and into the evening in the spring.