Hi I was browsing a domestic flight between JFK and LAS as well as LAS to TPA via ORD.

I was playing the dates between 2nd June to 8th June. I notice several routes have very massive flight number changes between 6th and 7th June. For example, ORD to TPA flight number changes are from AA1510/AA227/AA2504 on 6th June to AA1101/AA1464/AA2409. Flight time is changed within 5-10 mins difference from old flight number.

So is the JFK to LAS flight numbers. 2 daily on 6th June but increase to 3 daily on 7th June. The flight numbers seems to revert back to AA days on this route.

I wonder if this is a system wide flight number realignment happening over night? Anyone with inside info?