I would like to leave early enough to get there and set up camp before dark on Friday. If you get there after dark or on Saturday, you probably won't have any shade for your campsite . . . and it has been known to be HOT. Then again, one year I had to wear a jacket at night, so you never know.
I would like to head over that way any time after 1:00 PM but before 5:00 PM.