Depends on the time of the year.
Early season bow, I don't even bother hunting in the morning. You're just asking to spook deer on the way in and most of the time, they're in bed before shooting time anyway.
Early Pre-Rut - I still prefer afternoon slightly, but I do start seeing more deer in the morning, so on mornings when a cold front has come through and there's a big drop in temp from the day previous, I'll hunt the morning through about 11.
real pre-Rut - morning and evening are both great.
Rut - all day long baby, I shot the biggest buck of my life thus far(unfortunately didn't recover it) at 11:30 am on a fairly warm day November 11, which is late rut around here.
Post rut - Morning and evening are good....depends on the day and how close you can get to bedding/food that's close together.
Late season, back to evenings.