Teen Is A Time Traveler Or Suffering From Mental Illness 28 Days Before The World Ends

During the presidential election of 1988, a teenager named Donnie Darko sleepwalks out of his house one night and sees a giant, demonic-looking rabbit named Frank, who tells him the world will end in 28 days. When Donnie returns home, he finds that a jet engine has crashed into his bedroom. Is Donnie living in a parallel universe, is he suffering from mental illness - or will the world really end?