That's not a fair question. It depends on the set up and who else may be in there. If you're deep in the woods I'd say be in your tree no later than 4. A field edge, maybe 5. That said, you're really screwing up your chances wandering in that late. And if I had been sitting in a tree since 2 or 3 and some yoyo comes walking by on his way to a tree at 4 or 5, well I'm ticked. You got to do what you got to do if you're pressed for time, but it limits you. If you're running late rather than pick and dilly dally your way along. Walk quickly and quietly as you can straight to the tree and get settled as fast as possible.