Freaky Friday is a 1976 American fantasy-comedy film directed by Gary Nelson, with the screenplay written by Mary Rodgers based on her 1972 novel. The film stars Jodie Foster and Barbara Harris in the lead roles. John Astin, Patsy Kelly and Dick Van Patten are featured in supporting roles. In the film, a mother and her daughter switch their bodies, and they get a taste of each other's lives. The cause of the switch is left unexplained in this film, but occurs on Friday the 13th, when Ellen and Annabel, in different places, say about each other at the same time, "I wish I could switch places with her for just one day." Rodgers added a water skiing subplot to her screenplay.