Would You Just Make Up Your Mind?!

It drives me nuts! My supervisor tells everyone that we will be leaving at midnight(I'm supposed to leave at eleven because I come in an hour earlier than everyone else), then at the end of the night, no one knew what time we would be leaving! Eleven o'clock came, and I tried to turn in my paperwork, and he said to me, "You aren't planning on leaving, are you?" "Yes," I replied. "You aren't going anywhere until I tell you you can leave." he promptly announced. Well, two hours overtime is fine with me, it's just nice to know about it ahead of time.