[tz] Reason for removal of several TZ abbreviations

Brian Inglis Brian.Inglis at SystematicSw.ab.ca
Wed Dec 6 18:09:54 UTC 2017

On 2017-12-06 10:58, Guy Harris wrote:
> On Dec 6, 2017, at 8:50 AM, Brian Inglis <Brian.Inglis at systematicsw.ab.ca> wrote:
>> On 2017-12-05 14:29, Guy Harris wrote:
>>> So, for doing a script to do the equivalent of what macOS and iOS do, you'd
>>> want more like "get your external IP address, geolocate it, and hand it to a
>>> program with a set of shapefiles for tzdb regions". See, for example
>>> 	https://github.com/evansiroky/timezone-boundary-builder
>>> (to which
>>> 	http://efele.net/maps/tz/world/
>>> now refers people).
>> More likely query the underlying geodatabase for the time zone region, often
>> indexed by the minimum bounding rectangle [min x, min y[ - [max x, max y]
>> surrounding the possibly non-convex hull, then resolve muiltiple hits by
>> checking the interior convex polygons contain the coordinate, or equivalent tests.
> That's what I meant by "hand it to a program with a set of shapefiles for tzdb regions".

Sorry, to me a shapefile is an external data format used for interchange between
GIS GUI products, distinct from the geodata used for its generation.

Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada

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