The sequel-prequel
X-Men: Days of Future Past will most likely be set in the 1970s for the majority of the film -- if you believe this casting call, that is. The casting call went out seeking participants of ages 12-75 and of all ethnicities. Filming is set for April 2013 through August 2013.
X-Men: Days of Future Past is set for a
July 18, 2014 release.
Source:
Comic Book Movie