I used to think it was a science fiction show in which the basic plot is:
There is a time machine that can send someone back in time exactly 24 hours from our current start point. No more, no less. Jack works for the government and constantly goes back in time to save people, prime ministers, presidents, buildings, and various other things that can be destroied if not for the magical time machine. Every episode starts out with something horrible happening, and then Jack goes back in time to try and stop it before time catches up with him.
I was then told that, no, this is not what the show was about. It deals with 24 hours in a day in one season. "Oh well, screw that." I said, and walk away.
My concept is way cooler than what the show really is. Once I get my Bachelors in Dec., I'm gonna go make a TV about that. Time Travel is bitchin' concept (even though it isn't all that original).