Well, all the cases where an entire country is in one time zone, you're done. Same for the US when a state is within one time zone. Beyond that, it can get tricky. For example, taking the 3xxxx range of zip codes in the US, it has subranges. 300-319 and 399 are Georgia, straight Eastern. 320-349 is Florida, of which a small portion is Central and the rest Eastern. 350-369 and 386-398 are Alabama and Mississippi, respectively, straight Central. Finally, 370-385 is Tennessee, again split but this time with a majority in Central. So the fundamental problem is to first identify the place covered by a given point, then put that point in a time zone. -----Original Message----- From: Olson, Arthur David (NIH/NCI) [E] [mailto:olsona@dc37a.nci.nih.gov] Sent: Thursday 23 October 2008 10:21 To: tz@lecserver.nci.nih.gov Cc: heaivilin@hotmail.com Subject: FW: list I'm forwarding this message from Nathan Heaivilin, who is not on the time zone mailing list. Those of you who are on the list, please direct replies appropriately. --ado From: Nathan Heaivilin [mailto:heaivilin@hotmail.com] Sent: Wednesday, October 22, 2008 10:33 To: tz@lecserver.nci.nih.gov Subject: list To Whom it May Concern, I am trying to find a world list of Time Zones by Zip Codes and/or Area Code(and their respective foreign number) in sometype of downloadable format (CSV, XML, Excel, etc). Example: USA 33647 -6:00 GST USA 95400 -9:00 GST Europe xxxxx -x:xx GST Africa xxxxx +x:00 GST Does something like this exist? If so, do you have a copy available for download? If not, do you know where I can get it. Just trying to figure out a way to tie an address or phone number anywhere in the world to a time zone. Thank you very much for all of your assistance. Sincerely, Nathan Heaivilin