How long is a half day tour to Badaling on the Great Wall?

I would like to know how many hours would I be spending on the Great Wall to Badaling if I chose this option? I am only in town for the day so I would like to just spend a few hours at the Great Wall before heading back. I understand it is 2 hours travel time = 4-5 hours traveling time. But how many hours actually at the Great Wall? Thank you!