Here is the timeline for the events in the Arcadia Chronicles. It has a fairly accurate list of all the major events that took place in the series. Though because of the nature of the events, there are spoilers for them.
NOTE - The dates here were estimates taken from the Megaman X wiki back when it had the exact series timeline posted (viewable here
Though for ease of use, I prefer people just to use the 21XX style designations rather than give exact dates.
2175 - Megaman X8
2175 - Chaos Advent (3 weeks after X8) - Focuses on the Rookie Hunter team 66.
2210 - Command Mission
- X, Zero and Shadow (a new hunter) go to Giga city to stop an insurrection.
2210 - Dr. Weil is born (NOTE - The MM wiki timeline states the Weil is born in 2230... This is where my story deviates.)
2228 - Attention Rookies: Zero. (This is where we're playing through now.)
2230 - Attention Rookies (55 years after CA)
2260 - Attention Rookies 2 (30 years after AR, Weil is now 50 yrs old.)
2260 - Destiny In Arms (85 years from CA to DIA and several months after AR2)