How do they know that it's a flash forward? 'Coz there are some people who remember seeing the calendar in their flash forward. However, after some investigations, turns out that there are some people who didn't black out during those minutes (I don't know yet why this happens) and there are also some people who don't see anything during their black outs.
Those people who don't see anything feel that there's a chance that they might be dead already by then. One of them is engaged to a beautiful woman, but after the black out, he's confused 'coz he feels that he can't fight "fate". After all, he finds out that somebody else has a flash forward where she witnesses his death. How are you supposed to go on living after getting such information?
Another person "sees" himself being back to be a drunkard in his flash forward. This guy's wife sees herself with another man in their mutual house in her flash forward. They both finally confide to each other about what they see in their flash forwards, so the relationship between them is now tensed and there's less and less trust as the tension grows.
One person is actually about to kill himself when the black out happens. In his vision, he sees himself with a beautiful woman 6 months ahead and thus when he gains consciousness again, he decides that life is beautiful (or will be beautiful in 6 months' time), so he's determined to find that woman in his flash forward.
Another man sees something disturbing in his flash forward, so he decides to end it right then and there by killing himself so that he won't cause grief to those people he sees in his flash forward.
My question is: What's the use of knowing the future then? If the future you "see" is good, then it'll probably do you good (that's if you believe it and you're not skeptical), especially if you're stuck in a rut and in the flash forward you know that things can change in months or years. But if it's bad, won't it ruin everything, esp. if you have a fatalistic POV?
It's interesting to watch those people with different personalities handle this "flash forwards", though. :-))) I myself think that there's no just one linear path to the future. People CAN change and there are so many different factors involved in one's life...the only sure thing that'll happen to everyone is death.