Also be aware that if the weather has been bad in the previous week and they are running behind they may start play earlier than scheduled. Remember that your ticket gets you access to the whole area and play starts on the outside courts before the show courts. I suggest you also look at the restrictions on what you can bring into the ground so that you don't get stuck having to queue to drop things off in left luggage.
Also, if you do leave before the close of play, please leave your ticket in one of the special bins or get it scanned so that the Club can resell it (for charity) and someone else can experience the magic of Centre Court.