I’m a fan of Stephen King, and 11/22/63 is one of his best. There’s more humor than horror, and a fantastic, convoluted run-up to one of the most infamous moments in American history.
An English teacher is shown a hole in time that leads to a bright, sunny day in 1958. The teacher decides the best thing to do is travel back in time and prevent the Kennedy assassination, five years hence.
However, spending five years in the past isn’t easy, and there are complications he never could have predicted.
Recommendation: Read it. It’s a massive tome (850 pages), but King knows how to spin a story, and he’s in top form here.