Deja Vu is more about having the feeling that you have done something before. Having a dream before the event is a premonition. I used to get this frequently when I was younger, having a dream about a future event. Sometimes the event was hours into the the future, sometimes weeks but a few times it was years. The longest was 30 years, from having the dream to when the event occurred. When the events occurred it was like watching a familiar movie where all the players, people you saw and heard in your dream, spoke the dialog that you heard. Weird and begs the question: "Do we really have freewill or is life predestined merely to have the experience?"