I prefer to get into the stand well before daylight. In younger days, I made it a point to be a full hour before light, but as I get older, I arrive a bit later. Last year, I hunted the morning after we changed back from daylight savings time. Naturally, I screwed it up, and it was full daylight before I got in the stand. I feared it would be a wasted morning, but shortly after I got settled in the stand I killed an 8 point buck.
I still prefer to go in early, but I am not convinced that the cause is lost if I arrive later. In addition, I have seen a lot of deer during the middle of the day. I have been hunting regularly since 1964 and have spent a lot of hours in a stand. I guess the best time to hunt is the time you can get in the woods.