Marty McFly: "Where are we? When are we?"
Doc: "We're descending toward Hill Valley, California, at 4:29 pm, on Wednesday, October 21st, 2015."
Marty McFly: "2015? You mean we're in the future?"
Jennifer: "Future? Marty, what do you mean? How can we be in the future?"
Marty McFly: "Uh, Jennifer, um, I don't know how to tell you this, but I... you're in a time machine."
Jennifer: "And this is the year '2015'?"
Doc: "October 21st, 2015."