Continuity mistake: The money the guy puts on the counter when asking about the Trix disappears with no one touching it. (00:14:00)
Continuity mistake: When John falls over at the clinic, the wetness of his shirt changes drastically. (00:29:00)
Continuity mistake: Near the start in the bar, the blue label on John's beer keeps disappearing and reappearing instantly. (00:12:30)
Answer: Films are basically never set exactly when they're released. Most likely they just picked a random date around the likely time of release, but scheduling changed. Alternatively they just picked an arbitrary date in the future for the newspaper, but a date in the recent past would have worked just as well.