The Hills Have Thighs was based on the movie The HIlls Have Eyes that was released on what date? 
The Hills Have Thighs: The Hills Have Thighs is a 2010 American made for cable erotic film written and directed by Jim Wynorski under the pseudonym Salvadore Ross. The Hills Have Thighs:  It is based on the 1977 horror feature "The Hills Have Eyes" written and directed by Wes Craven. The Hills Have Eyes (1977 film):  The film was released in cinemas on 22 July 1977 and has since become a cult classic.
22 July 1977