The movie is an interesting contrast to Groundhog Day. The plot is roughly the same, with the same day repeating and only one man aware that it is happening. One difference in 12:01 is that the story attempts to explain the time loop with some dubious sci-fi mumbo-jumbo that would have been better left out. If you've seen any of the new Star Trek spinoffs shows, you know the kind of mumbo-jumbo I'm talking about. Another difference is the protagonist is a young man, which imparts a slightly different spin on the plot than Bill Murray's middle-aged, burnt-out newsman in Groundhog Day. In particular the younger character is more motivated to rectify the problem than Murray's character, since the latter hated his life.
This movie does not work as science fiction. It is much more interesting as a study in character, seeing how an ordinary young adult would respond to this unique crisis in his life. As such, it is interesting, but Groundhog Day gave the theme a better treatment.
If you liked 12:01 and Groundhog Day, I strongly recommend the novel Replay by Ken Grimwood. Same theme, except the main character repeats his LIFE. In Replay, the time-loop idea is fleshed out in a way that could never be done in a movie. Like Groundhog Day, Replay doesn't try to explain the loop, which allows you to concentrate on the characters. Highly recommended.