Most of us have already seen X-Men Days of Future Past, and almost all of us have seen the trailer for X-Men Apocalypse, but is the timeline messing with us.
In the end of X-Men Days of Future Past, we saw Logan inside X-Mansion reuniting with his old friends (most of them dead in earlier movies), but was that just the result of Apocalypse?
Here's my theory.
In the X-Men Apocalypse trailer, everyone was younger, Jean, Cyclops, And Charles, but in the end of Days of Future Past, everyone was their regular age from the franchise, so this means that the younger versions of the X-Men have already finished the war with Apocalypse.
Logan would have already went back in time to stop Mystique, and Raven would have defeated Magneto, but Logan ends up drowning in the lake (figure of speech, he was still alive). When Logan wakes up, he reunites with OLDER Xavier, Jean, and Scott.
So, the timeline would have been Days of Future Past, until the moment before Logan wakes up. In that point, X-Men Apocalypse would have started, with the X-Men winning the war, and then Logan would wake up, back in Future Past
This theory explains the coincidence of the timeline, and the fact that the X-Men will win the war against Apocalypse.