The IATA code for an airport sometimes change. E.g., IDL was changed to JFK. Where can I find the log of IATA code changes, preferably with the dates of the code changes?
Maintainer of OpenFlights.org here: as far as I know, you can't.
I'm currently working on extending the existing OpenFlights datasets to add the dates when airport started/stopped operating, but even this won't easily let you match airports that change IATA codes straight up. It's not as simple as comparing coordinates, because there are several cases where one physical airport/field/runway has multiple IATA codes, eg. Basel/Mulhouse EuroAirport.