The film , X-Men : Days of Future Past , is the sequel to both X-Men : The Last Stand , 2006 , and X-Men : First Class , 2011 .
A British-American venture , the film is based on the fictional X-Men characters that appear in Marvel Comics and is the seventh installment of the X-Men film series , the sequel to X-Men : First Class ( 2011 ) .
X-Men-COLON- Days of Future Past