Groundhog's day was actually a good movie, but it made even less sense than this picture.

How is it physically possible to relive the same day over and over again? Which run-through of the day will other people remember? They would have so many recollections of the day their heads would most likely implode.
Time is linear. There is no way to slow down or speed up time, much less reverse it. There are so many logical fallacies on Groundhog's Day that it really detracts from the movie.
Also, what is preventing Phil from staying up until 6:00 am? If he does, then what? Does the universe collapse into a tiny dot of superheated matter? Does his existence split into two?
Last but not least, even if this was possible, why does he remember the day and no other people do? Memory is a physical thing, a mapped-out set of circuits in the brain. Why don't those get reversed to their previous state? Why are all the other peoples' minds wiped clean but not Phil's? Everyone else would also remember that day and are stuck in it, but Phil is the object of attention.

Case in point: What the hell?