A fictional time or date by which something should be completed, ususally according to a movie, television show, video game, science fiction book, or bullshit artist.
Example 1:
Dude: "It's 2015. Weren't we supposed to have hoverboards like Marty McFly in Back To The Future II by now?"
Girl : Nah, "2015" was just a movie deadline. We're just kicking that hoverboard shit off in 2015 and the tech for it kind of sucks right now.
Example 2:
Girl: "Jake said he was going to marry me by 2012. It's 2015 -- I guess that 2012 bullshit was just a 'movie deadline.'"