Harry Potter and the Chamber of Secrets - Wrong Time!
At the bit where Ron and Harry are trying to get through the wall to Platform nine and three quarters, Harry says "It's exactly 11'o clock! We've missed the train!" If you look closely behind them you can see that it is ten to 11. So it's either Harry (Daniel Radcliffe) can't tell the time or the producer got the clock wrong.
Actually, if you pay attention, just after they ran into the wall and the conversation with the platform conductor. Harry says to Ron, "Why can't we get through?" then the clock behind them chimes and when Harry looks up at it the hands on the clock are pointing at 11 o'clock exactly (little hand on the 11 big hand on the 12). That's when Harry says, "The train leaves at 11 o'clock sharply, we've missed it." This is not a slip up at all.
Either you can't tell the time... no you just can't tell the time. It does say 11 o'clock. The small hand represents the hour. The big hand represents the minutes. I suggest you go back and watch the movie one more time.