Try to consider what will happen at the end of the evening. What time do you think guests will start thinking of leaving. What time is the DJ playing until? Will you have a shuttle for your hotel guests? Will you have an "after party" planned for guests who want to continue the night? Will you provide food for the guests towards the end of the event? Some people will bring out snacks around 10pm. Thinking of your guests and how their night will end means that they will have a good time from start until finish.