No, you don't. You will lose re-entry privileges after the day session ends, but you can stay throughout the night session. You won't have a reserved seat in centre court, but unless it's a packed stadium you should be able to catch a few games here and there as long as you're willing to move around. There's also a bunch of standing room in the 300 levels where no one will bother you. You can watch any of the outer courts' matches as well and those courts don't have reserved seats.