I believe they closed the slide around 9 pm last year and the pool was opened until 10 or 11 pm. We were there the last week of August last year. The quiet pool over at BCV was open 24 hours but no lifeguard after 10 or 11 pm. The week we were there a man and his son swam every morning around 7:00 am. I would sit on the balcony and watch them as I had my coffee. Too early for me.
You probably could call the resort directly and ask them the hours for SAB for that time of year. Of course, I'm sure they'll tell you (like always) that hours are subject to change.