Eric Muller
wrote:
"To my knowledge, there is not yet a
publicly available shapefile that covers all the tz timezones, but there are
shapefiles that cover "modern" time zones."
World
Time Explorer (a Windows program that I made) includes a shapefile that is
including all tz timezones. Additionally, it contains a DBF file for the
shapefile that both represents the names of the shapes, but also connects
each shape to WTE's own timezones. Note that often a given timezone spans
many little pieces since the land surface is split into many islands. The only
problem of mapping the tz timezones to the WTE timezones is just the naming
convention, for instance the tz timezone Europe/Uzhgorod is in WTE "Ukraine,
Uzhgorod". In most cases this should be straightforward, but some might need a
little bit of "digging". Timezones are present in the city.txt file with an "@"
in front, and represents the subsequent cities not having an "@" in
front.
You can use WTE to
calculate the map colors for any given time since 1850 till today, where each
color represents a given GMT offset. There is an example of how this looks like
here: http://www.worldtimeexplorer.com/WorldMapBig.gif
but also note that calculating the colors is only activated when you have a full
(paid) license.
On the other hand I
consider the shapefile to be publicly available, although I have not supplied it
with a proper GNU free license or similar license.
P.S: I use
"timezone" instead of "time zone" deliberately, although I perhaps agree that
"time zone" is better English grammar. One reason is that the Danish language
would always put together the words to a single word with a new independent
meaning, in Danish "time zone" is "tidszone". But also it is clear that a Google
search for "time zone" gives a whole lot of hits for articles referring to time
and another pile of hits referring to zone, which really have nothing to do
with "time zone". Just my 2 cents.
Regards,
- Jesper Nørgaard
Welen
Jesper Nørgaard Welen
Email:
jnorgard@Prodigy.Net.mx
Project Leader (Líder de Proyecto)
Software
CIMMYT - Centro Internacional de Mejoramiento de Maíz y
Trigo
Dirección: CIMMYT Int. c/o Jesper Nørgaard
Km. 45, Carretera
México-Veracruz
El Batán
Texcoco, Edo. de México
CP 56130
MEXICO
Tel.: +52 (55) 58-04-20-04 ext.
1374
Fax: +52 (55) 58-04-75-58
Tel. Casa:
53-10-05-95 ó 53-10-97-78
Download the shareware program World
Time Explorer, I made:
http://www.worldtimeexplorer.com/index.html
