We did this with all the adults in my DH's family in May. The fireworks that night were at 9:00. We made ADR at 8:00. It worked out perfect because we had to wait about 20 minutes for the table. Our server asked if we would like our meals timed to the fireworks. We had completed our orders and had just finished our appetizers when our server came around to inform us that we had 10 minutes to the fireworks. We were not by the windows, but he showed us to the observation deck and we watched them from there with a glass of wine. It was very nice and they pumped the music to the deck. It was perfect weather and very romantic because there were few people out on the deck. I definitely recommend it. Be sure to let your server know that you are there to see the fireworks and would like the meal timed to them. With a 9:20 ARD you should be fine if you don't have to wait on the table too long.