Technically, isnt there just as good a chance you will bust the deer at 4 am compared to 5 am in most places?

Depending on where I hunt is how early I go in. If I walk through ag fields like cooter said, I wait till later to go in. If I am hunting where deer movement is hottest RIGHT at legal hours, I am there well before dark...if I am hunting out in the middle of the woods in a travel route sort of place, i wait till I can see where I am walking without a light before I head in. I am 12x more quiet this way, and in this type setup, the deer could move through at any time. Just as likely to bust one coming through at 4 am as 9 am.