Peter Landesman adapted the Parkland screenplay from the book Four Days In November by Vincent Bugliosi, and makes his helming debut with the picture. The story recounts the events at Dallas’ Parkland Hospital on the day John F. Kennedy was assassinated. Zac Efron, Marcia Gay Harden, Billy Bob Thornton, Jacki Weaver, Paul Giamatti, Tom Welling, Mark Duplass, James Badge Dale and Colin Hanks star. The film world premieres at the Venice Film Festival which begins next week. Exclusive Releasing has set a September 20 U.S. release.