Early season I' ll usually stay until sometime around 11:00. Sometimes longer if action dictates, and it' s not boiling hot already. Last year I killed a doe on opening day (early Oct) at 12:30. Action was just too good to get down. Even if it' s a little slow, I' d just rather be up a tree...than doing much else.
Later in the season, I' m there for as long as it takes. There' s an awful lot of mid day action come Nov.