Up until the second Wolverine movie it all pretty much fits, barring some stupid character inclusions in the first Wolverine movie, so you can take...
X-MEN: FIRST CLASS
X-MEN ORIGINS: WOLVERINE
X-MEN
X2: X-MEN UNITED
X-MEN 3: THE LAST STAND
THE WOLVERINE
...as all being one timeline (along with Daredevil, Elektra and the first two Fantastic Four movies)...
LOGAN is a slightly different world, where the X-Men are remembered as heroes, and whatever you think you know of their story, only a quarter of it happened like that, as Wolverine himself states in Logan.
The LEGION TV series is also a separate world, as that is modern day, but the government are only just learning about mutants.
So there you've got 3 different timelines.
... as for Days Of Future Past .... I don't see how it follows from the original trilogy, because NEITHER version of 1973 in that movie leads to the world we see in the first X_MEN ...
It starts with a timeline that goes...
FIRST CLASS >>> dude gets assassinated >>> future full of sentinels,Wolverine sent back (after several timeline changes by Bishop)
... and ends with a timeline that goes ...
FIRST CLASS >>> DAYS OF FUTURE PAST >>> APOCALYPSE >>> (DEADPOOL) >>> Future Wolverine wakes up in at the end.
... at which point,any events leading up to the future full of Sentinels that did mirror the original trilogy and Wolverine movies have now been re-written, as Jean is still alive and we also have a different version of Wade Wilson running around in his own movie.
I watched the movies in this order either side of seeing LOGAN at the cinema and it really works a hell of a lot better than watching them in release order ...
X-MEN ORIGINS: WOLVERINE
X-MEN
X2: X-MEN UNITED
X-MEN 3: THE LAST STAND
THE WOLVERINE
LOGAN
X-MEN: FIRST CLASS
X-MEN: DAYS OF FUTURE PAST
X-MEN: APOCALYPSE
DEADPOOL
.... So, No, Logan doesn't ruin the events of Days Of Future Past for me one bit.
