Europe is on "winter" time versus US still on DST

Tracking AF664 today.

Flight shows as leaving Paris at 10:45 CET, scheduled to arrive in Chicago at 12:47. This should be 1:47.
This is because Paris is currently 6 hours ahead of Chicago. Once the US switches to winter time, the time difference will go back to the usual 7 hous.

Not able to reproduce what you’re describing. FlightAware is accurately reporting that Chicago is in CDT currently.

I see that the ETA is 13:46 CDT, so I suspect you were just seeing an incorrect ETA that we received from ETMS which has been subsequently updated. Not an issue of timezone confusion.

Internally all times are received and stored as absolute zulu (UTC) times, so there would never be a situation where a timezone mismatch would result in a miscalculated ETA like you’re describing.