I made a reservation for 9:30pm on the day I arrived in New York. I arrived a little early, but when I asked the staff at the entrance, they let me in without any problems. There was no line at all at this time, and there were not many tourists, which was great. However, it was windy and very cold at the observation deck. It was mid-November, and even though it was warm during the day, it got cold at night. If you are going at this time of year, I recommend that you dress warmly. The night view was very beautiful, and it really made me feel like I was in New York!