Jerry, I believe the data was somehow extracted from the unix timezone files/database. Unfortunately the tool that did the work doesn't seem to be included with the ref-timezone package. If we had the tool, then it might be possible to only populate the database with the required timezones.
After considering the need for repeated events and the use of intervals, timezone data is going to be required.
I'm wondering if in the future we could hack to_char to output a date in the timezone we want, assuming data is in GMT.
