February 14, 2007 tools

Detailed Time Zone Data

A long time ago (2000), I was fascinated with turning a phone number into a time zone so I could tell what time it would be somewhere before I called and woke anyone up (this happened too often : ).

As part of that work, I quickly realized that info in Windows for time zones wasn’t detailed enough, so I began looking elsewhere. I found the Time Zone Map Group, which maintains time zone data for all over the world backward through time. This is an amazing accomplishment, since they have to account for every law change as each tin pot dictator comes to power, e.g. George W.

At the time, they had a custom format for the data (and they probably still do, as far as I know), so I wrote a utility to translate the tz format into XML for easy parsing. I literally haven’t touched the tool since, but with the recent time zone law changes in the US, I thought folks might be interested. Enjoy.