If there are a lot of bears in the area, the greedy ones will show up at any time. It's the older (smarter) ones that hold back. This is in areas where the hunting pressure is moderate to high. If there is low pressure, and if the critter is familiar with the fellow to brings the bait, a bear could be on it before the baiter is back in the truck. But, in general, prime time seems to be that last 1/2 hour of light in the evening. Just remember, like most game, anything can happen at any time, but some times are better than others.
