From watching the trailers, the film's earliest date is the
late 1890s where 12-year-old James Howlett (Wolverine) kills his biological father Thomas Logan and wounds his half-brother Dog (Sabretooth)...
From there we go to WWI in the
1910s where the 30-year-old Logan (Wolverine) fights...
Fast forward to WWII in
1944 where Wolverine re-encounters his estranged half brother Victor Creed, whom he most likely will not recognize from the events that took place 50 years earlier. The two 60-year-olds fight side by side on D-DAY...
Enter
early 1970s Vietnam, where the 80-year-old Logan boys (Wolverine and Sabretooth) have become mercenaries in the name of the U.S. Army. At this point they get captured by the opposition and Stryker somehow gets a shot at making a deal with the two.
Judging by the clothes the women are wearing in this photo (and Gambit's sideburns), the Gambit scene(s) take place in
late 70s New Orleans. Gambit encounters Wolverine and Sabretooth for a yet to be revealed reason.
Storm was in her late 20s in X1 which was set a few years after 2000. That means she was a little girl at some point in the
late 70s. Cyclops was supposed to be in his early 30s in X1, so that explains Tim Pocock - the 20-year-old who plays Scott in the movie.
So the film pretty much covers a hundred years of Wolverine/Sabretooth history.