Jesper Norgaard Welen tried to send the following email to the list on July 1, but apparently didn't get through. I am enclosing it in the hopes that it does get through this time. From: Jesper Norgaard Welen [mailto:jnorgard@prodigy.net.mx] Sent: Domingo, 01 de Julio de 2007 16:15 To: 'tz@elsie.nci.nih.gov' Cc: 'emuller@adobe.com' Subject: RE: Geographical boundaries for the continental US tz zones Hello, Eric Muller I send my comments to your US timezone map directly to the TZ list since I think it could be of common interest in the list and also to urge members to send comments where appropriate. My newest map for World Time Explorer you can download from http://worldtimeexplorer.com/tztables.zip * Navajo/Hopi reservations There is an important Hopi population that you have not included around Latitude 36.14 Longitude -109.40 that I would recommend you to include (see WTE map) * Nevada on Idaho time The city Jackpot in Nevada (and several others like Owyhee and Mountain city) are on Idaho south time, or Denver time if you will. I have included it in a 25 km broad strip of northern Elko county, however just based on common sense when there were cities 12 km below the border that were on Denver time, and I would not expect their time to stop 100 meters outside the city boundary, but note that it is arbitrary, and quite possibly not quite 25 km. Jackpot itself is quite close to the border to Idaho. * Idaho county split (Idaho state) I have a northern and southern part of Idaho county, which I got from another timezone map (possibly Manifold map). This indicates that the southern part of Idaho county is on America/Boise time while the northern part is on America/Los_Angeles. Note that this is *not* documented in the tz database - I am still a bit ambivalent which one to believe. If you want pure tz database functionality, the timezone border should be a little further south. * Alaska I have the same doubts as you. However, I have implemented a solution, however arbitrary it is, seems much better than just putting Juneau for all of Alaska. The Nome area is small, while most of northwestern Alaska is set to Anchorage time. Then there is a Yakutat area and a Juneau area. They are all based on counties in this area. Comments are welcome. * America/Kentucky/Louisville This city belongs to Jefferson county of Kentucky, so I just assumed that this would comprise the Louisville timezone - however tz database needs to describe this - and include more counties if there are more. It just states the vague "part of Kentucky". * Sioux county North Dakota Tz database states "part of Sioux county" and that is exactly what you have included, splitting it around Latitude 46 Longitude -101.34. Where did you get shis from? I have included all Sioux county being on same time, but that most be wrong. * Cherry county Nebraska I see you have a different, more detailed split of Cherry county than mine. Where did you get this from? * Morgan county, Tennessee I recently discovered that this county is on CST/CDT, and included this in the western part of Tennesse. It's around Latitude 36.07 Longitude -84.56 * Alabama Note that (parts of) Chambers, Lee and Russell counties should be on America/New_York time, not on America/Chicago time. * Culberson county, Texas Note that the parts of this county including Nickel creek and Pine Springs are on America/Denver time. Regards, - Jesper Nørgaard Welen -----Original Message----- From: Eric Muller [mailto:emuller@adobe.com] Sent: Domingo, 01 de Julio de 2007 12:07 To: tz@lecserver.nci.nih.gov Subject: Re: Geographical boundaries for the continental US tz zones I have completed a first version of a map of the TZ timezones in the US. It is available as a shapefile at <http://www.efele.net/maps>. Comments welcome, Eric.