[Talk-us] Timezones in USA?

[L. David Baron]

On Tuesday 2016-05-24 22:37 +0000, evan.siroky at yahoo.com wrote:
> I found and read through this OSM mailing-list discussion about timezones from a few years ago: https://lists.openstreetmap.org/pipermail/talk/2013-October/068334.html  It seems there are mixed feelings for how to include timezone data in OSM.

Hmmm.  A long thread that I didn't read all of, but perhaps a brief
summary of the positions would be useful if you've read it?

> It seems the current methodology for adding timezone data is adding a tag at the highest level of administrative boundary that is completely encapsulated within a timezone.  For example, a state that contains multiple timezones would not have a timezone tag, but instead all of the state's counties would.  However, there are still a few small quirks that would not be covered by this methodology: 1) cities that use a different timezone and 2) timezone boundaries that don't share a boundary with any other administrative boundary.

This appears (as you point out) to be problematic when timezone
boundaries mostly but not completely correspond to other polygons.

Perhaps it would make more sense for the timezones to be their own
areas on the map, rather than being represented by tags added to
existing areas?  (Most or all of the nodes for such areas should
already exist.)

> I'm asking all of this because I'm interested in improving the data quality of timezone boundary data.  I am aware of the shapefile of timezones at http://efele.net/maps/tz/world/, but it doesn't include territorial waters and the underlying data doesn't appear to be open/editable.  It seems like OSM could be a place to store at least part if not most of the timezone boundary data.

It seems worth trying to use the existing work there rather than
duplicate it.  The author seems like he might be willing to help
with such an effort based on his commment in
http://mm.icann.org/pipermail/tz/2015-November/023001.html

(Getting territorial waters, or maritime rules in general, correct,
may be a lot of additional work.)

I suspect that talk-us may not be the right forum for discussion
what ought to be a worldwide project, though.

-David

-- 
𝄞   L. David Baron                         http://dbaron.org/   𝄂
𝄢   Mozilla                          https://www.mozilla.org/   𝄂
             Before I built a wall I'd ask to know
             What I was walling in or walling out,
             And to whom I was like to give offense.
               - Robert Frost, Mending Wall (1914)
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: not available
URL: <http://lists.openstreetmap.org/pipermail/talk-us/attachments/20160526/c131053b/attachment.sig>