I'll give more tangible clues in the next one. I think a lot of people I know would get it instantly with the first one, but a lot of the people I know are film students... (although that doesn't make as much difference as you might think it does. The average player of the movie picture game >>>> average film student in terms of knowledge of random movies)
You can go to imdb and do a search by keyword time-travel, but here are a few off the top of my head
Back to the future trilogy
12 monkeys
Butterfly effect
Looper
Paycheck
Deja Vu
Next
Donnie Darko
Source Code
Terminator
Premonition
Planet of the Apes
Hot Tub Time Machine
Safety Not Guaranteed
Harry Potter
Primer (is this your movie?)
You can go to imdb and do a search by keyword time-travel, but here are a few off the top of my head
Back to the future trilogy
12 monkeys
Butterfly effect
Looper
Paycheck
Deja Vu
Next
Donnie Darko
Source Code
Terminator
Premonition
Planet of the Apes
Hot Tub Time Machine
Safety Not Guaranteed
Harry Potter
Primer (is this your movie?)