Late night events and weekend tournaments are no longer considered special circumstance; they are the norm. It is especially critical to fuel your body appropriately during tournament play since you are usually competing several times a day without optimal recovery time.
Usually a quick snack an hour before competition or practice is ideal for most. Snacks post event are also important. While selecting a carbohydrate-rich food pre-event is best, adding in some protein to your post-event snack/meal is critical to maximize glycogen stores and aid in muscle repair.