Time Zone Data Update

I know a couple of points where I change timezones on a trip I make every week or so. I will see if I can get the coordinates.

As you realize, there will be a lot of one-at-a-time updates. But - thanks for starting the effort.

Actually I am pretty confident it is already mostly accurate, and that the vast majority of exceptions have already made their way into my data. I did a LOT of research.

But certainly I missed some - and I am very grateful for a heads up for any that slipped by me. I look forward to getting your corrections.

{edit: DOH! I now realize you were referring to edits to the POI's, not to my time zone data.)

Steve, updating the POI list would be great as every time I travel west to AZ the time change indicated by the current POI file is off by about 10 miles. Here are the coordinates for the zone change on I-10 just outside of Van Horn TX (-104.908438 31.042057).

How about some feedback on what would be a good naming convention?

The current list uses this this:

"Time Zone Change" - (road name) (state to state)
e.g.: "Time Zone Change - I-40 AZ to NM"

I'm thinking we need to add an element that indicates what time of year this time zone change applies, using "ST" for points that apply only in Standard Time, "DT" for points that apply only during Daylight Saving Time, and "YR" for points that apply year round (check out the home page animated gif at ontimezone.com if you don't know what I'm talking about)

I'd also shorten the label from "Time Zone Change" to "Time" to increase the odds that meaningful data will appear in a readable font on your tiny GPS screen.

e.g.: TimeZone_ST_I40_AZ-NM

It would also be easy to generate a voice-friendly companion version of the POI list that looked like this:

"Time zone change Standard Time Only I-40 Arizona to New Mexico"

[mikemeyersmotherinlawvoice]discuss[/mikemeyersmotherinlawvoice]

Here's a naming convention I would use.

-104.908438,31.042057,Time Change - Mountain to Pacific,I-10 TX to NM

It's pretty much identical to the current listing, except instead of having the location in Column C it tells what time zone you're leaving and which one you're entering. The location is moved to Column D. This also possibly solves the issue of Arizona, where you have the reservations on one time zone while Arizona follows another. So for Arizona to California, it could be written like this:

-xxx.xxxxxx,xx.xxxxxx,Time Change - Arizona to Pacific,I-5 AZ to CA

For places that don't observe DST (Arizona primarily), you can add to Column D a notation that DST isn't observed in that area.

There are over a dozen such DST anomaly borders on the map (Arizona accounts for only 4 of them), each of which only represents a time change during part of the year.

The problem is that a POI on one of those borders - which only apply part of the year - doesn't define an area, instead it defines the border between 2 different areas.

And when you cross from, say, southern NM into Southern AZ in the Summer, are you crossing from Mountain Daylight to Mountain Standard, or from Mountain Daylight to Pacific Daylight? It is defined both ways depending on the source (though Mountain Standard is actually correct). The whole thing is confusing to users.

I can't shake the feeling that each POI should specifically indicate whether it applies year round, only in DST, or only in Standard time. But if I'm off in the weeds feel free to haul me back.

These could be comments similar to the hours of operation of a store.

If you are thinking about "naming" the time zone changes. then just a pop-up that reads Time Zone Change Pacific-Mountain. If you try to get fancy such as You are now entering the Pacific Time Zone, it isn't true if you are headed East.

Having been through this discussion before in 2009, I have had the time zones on my website http://latvietislatvija.com/Time_Zones_USA.txt all this time and have tried to figure out the Arizona Indian borders. The only way I found but not implemented is to put it into several files. The first would place Arizona as a different time zone alert file. The second would only alert as we changed reservations.
I will put this file on POI-Factory and let you figure out how you want it to be. When I travel through Arizona I generally just remember that I have to remember that there might be a change.

That's essentially what I was thinking. If someone needed additional information though, could they not tap on the popup or banner bar to access the added info?

This program works great! I have the original time zone crossing POI file downloaded, and have noted several errors (including the lack of a point along I-24 near Chattanooga).

-Dave