Before 9pm the courtyard a Pat O'Briens is filled with people - adults, families, etc, enjoying some good food and drinks. Honestly, the courtyard is lovely all night long. On Tuesdays they have 2-fer-Tuesday with 1/2 price Hurricanes (and other speciality drinks, but you don't get the souvenir glass during this time) and 1/2 price appetizers (the New Orleans Spicey Cheese Fries are yummers) from I think 5 until 10. So Tuesday is a great night to go and get the most bang out of your GC.
The courtyard is separate from the piano bar section and is open air so if it is raining you're in trouble. But if it isn't raining it is a great place to relax and enjoy some good food and drinks.
Oh and also...if you do go there to eat, try to get Michael as your server. He is really terrific. Bryan and Marquise are great too but Michael is the best.