To me, being in the woods, all setup long before first light, is important. It gives the woods a chance to calm down and you're already set and waiting as deer continue moving before dawn.
That being said, of you cannot do that, then get in the woods whenever you can and stay the remainer of the day if possible. If you can be setup by 8AM, great, if not until 11AM, that's OK too. The point is to get your things in order and be ready to hunt as soon as you feel you can.
Good Luck!