Dusk and night are the best times in my area. I don't hunt with lights usually, but with a good scope, most clear nights with even half moon you can still pick up a good range... Full moons are easy pickings! Calling in morning and mid-day can be productive too, but it's usually more difficult. They are a lot more cautious in the light, and a lot less interested. They'll come up brazen and bold at night, but getting them to come into the open during daylight hours is much more difficult.