Traditionally it is from midnight till 9:00 am-9:30. Two shots. One at midnight and one in the morning. Depending on your connection with the girl it might end up multiple shots especially if it is her last day and you have a good connection with her. I mostly book overnight on her first or last day. The first one is cause they still have energy and the last one is cause they won't need to mother about next days work. Also easy way to talk you into multiple shots is tell her in advance if the service is good you will tip her more. Mostly it works and you get multiple shots and get the number for a fuckfriend in china