There are advantages to hunting certain locations at specific times of day.
QUESTION: I have been told to hunt the bottoms in the mornings and the fields and field edges at dark. Is this true?
ANSWER: It’s tough to give a concrete answer without more information about the region and habitat you hunt. However, I’ve hunted many areas where this is probably a good approach.
My experience in the Deep South (Alabama, Mississippi, Georgia) and the Midwest (Illinois, Iowa, Missouri) is that we usually hunt back in the woods in the morning for a couple reasons. Deer are already in the fields when you arrive for the morning hunt, so you’ll only blow them out if you try to hunt the fields and field edges in the a.m. Then, as the sun comes up deer are far less likely to venture back out into the open. You’re better off setting up back in the woods where you can intercept them on their way to bed.
When you ask about hunting fields, I assume you mean greenfields, crop fields or food plots. Those locations are typically more productive in the afternoon. You can slip in ahead of the deer and get settled before they come out to feed.
One more thought: If you really want to kill a big buck, you might consider setting up 100 yards or so back off the field edge, even in the afternoon. Older bucks often don’t venture into the open until after dark, and can sometimes be found cruising just inside the woods downwind of fields in order to scent-check does in the field.