Date: Wed, 30 May 2007 22:55:25 -0700 From: Eric Muller <emuller@adobe.com> Message-ID: <465E634D.2080301@adobe.com> | I am trying to figure out the geographical extent of the 19 continental | US timezones defined by tz. Sorry, I can't help with that, but your question is a fairly common kind of one - we keep having people attempt to draw maps from the timezone data. I don't believe that it is really particularly suited for that, nor that it should be. The aims of this project are to identify all of the distinct timezones that exist, as best we can - it isn't part of our aim to specify just who is supposed to use each of those timezones, that's what the local legislature or executive administration (or whatever) does - or attempts to do, usually out near what you'd like to be a nice clear boundary between zones there's actually lots of ambiguity. This project doesn't care - as long as each individual user can decide "my local time is always the same as that in New York city" (or wherever) then they can select data that is going to be correct for them. It is irrelevant whether their neighbours use the same zone, which side of some boundary line they're on, or anything else like that. This all means that we don't much care where the boundaries are and there's no reason that we should, even if there really are nice fixed boundaries. What is more important here is when someone discovers that some region uses a mapping from UTC onto wallclock time that isn't the same as any that we have, or when one of the existing ones changes its rules. The actual set of people that any of this applies to isn't so important (as long as it is more than 0, or it isn't worth distributing). None of this means that what you're doing isn't useful, and if and when you find errors in the zones, or the comments about the zones I'm sure they'll be corrected. It also doesn't mean that there aren't people on this list who can answer some or all of your questions - nor that you shouldn't have asked them. I'm just trying to discourage any (more) bending of the timezone data towards the needs of map makers - that isn't the objective. kre