GeoNames Forum

Hi all..

Maybe this question is a bit naïve: But where do the Olson timezones in the geonames database come from? Are they just entered along with the cities? They look very accurate, i.e. non-Pacific times in Oregon.

This post mentions polygons used by the webservice. Are the polygons also used to update which city belongs to which timezone?

I've spent some time doing a 'scrub' on the Olson timezones to find the zones that are "the same" (from now on), and I've plotted the corresponding populated areas on a world map. It's a total hack just to help me visualize this stuff: http://blog.time2call.net/ImageMap2/

Cheers,
Russ

Hi Russ

The same polygons used for the web service are also used for the cities. It would be too much work to determine the timezone individually for each city. The user interface for editing the cities does not even allow to enter the timezone as it is entirely based on an automatic assignment for the lat/lng.

Best

Marc

Hi Marc,

I was actually attempting to draw polygons around the timezones myself. Are the geonames timezone polygons available for public download?

Thanks,
Russ