Hi, I maintain a file that maps the zone name for about 1800 airports to their IATA, ICAO and FAA identifiers. For instance: # Toronto, Ontario, Canada - Pearson International Airport Link America/Toronto IATA/YYZ Link America/Toronto ICAO/YYZ Link America/Toronto FAA/CYYZ We append this data to tz's backward file and it simplifies life for us, since we deal extensively with aircraft routing information. I haven't been able to find anyone else that doing a similar thing and would like to make this data publicly available in the event that it would be of use. The need to do time calculations by airport ID isn't all that common, but if you need to, these mappings are really, really, helpful. Is there a central repository of other such add-ons to the tz database or some other way to let people know that this data exists? Rikk Salamat Crewsware Software Inc.