These days I do most of the work in coordinating the maintenance of the tz data. Alois Treindl <alois@astro.ch> writes:
- add boundary descriptions to each area with a different timezone history so that with given coordinates it can automatically be determined to which timezone history 'table' a given location belongs.
- add more details for the complicated timezone history of some countries, e.g. Canada, where other sources have identified more than 250 regions with different timezone history, whereas current tzdata has only 15 regions.
These are both quite worthy projects. Yay! To my mind, the second is easier. The main thing is to identify each region, give it a name suitable for the tz scheme (given the number of regions, I'd suggest 3-level names like "America/Ontario/Nipigon", much as we already do for Indiana), and to record the data in tz format (i.e., format suitable for the zic program <http://www.linuxinfor.com/english/man8/zic.html>). For the former, we'd need to settle on a data format. I'm by no means an expert in the GIS area, but if you look at the "Time zone boundaries" section of <http://www.twinsun.com/tz/tz-link.htm> you can find previous work in this area (none of it sufficient for tz's needs, alas, but it's better to start from something than from nothing). I'd prefer a format that is freely available, and that can be processed by free GIS tools like GRASS <http://grass.itc.it/>. We also would need to address the copyright issues. Currently the tz database is public domain. If this might be a problem for you please let us know.