Here is my personal view of the X-Men Movies Timeline. Keep in mind, I haven't seen all of them, so this is just the movies I have seen, or at least information from between films.
Continuity in films[]
X-Men: First Class (2011)[]
- Possible Date - 1963
X-Men: Days of Future Past (2014)[]
Future Sequences[]
- Possible Date - 2023
Past Sequences[]
- Possible Date - 1973
- 10 years after X-Men: First Class.
X-Men: Apocalypse (2016)[]
- Possible Date - 1983
- 10 years after X-Men: Days of Future Past (Past Sequences).
Logan (2017)[]
- Possible Date - 2029
Dark Phoenix (2019)[]
- Possible Date - 1992
- 9 years after X-Men: Apocalypse.