Hi, On 30 September 2010 20:27, Nick Austin <[email protected]> wrote: > I'm a user of TWISST, a free service run by volunteers that sends > tweets notifying the best viewing times for overhead passes of the > International Space Station. Earlier today they put out a request for > help via their web site: > http://twisst.nl/timezones > > In summary they need volunteers to help program in LAMP (Mysql 5.1, PHP 5.2). > > If your too lazy to follow the link here's the first few paragraphs > from the web site: > > ----- > "To send people correct ISS-alerts, we need to know in which timezone > they are. We need a script to tell us that." > > "To find out their timezone, we send peoples coordinates to the > Geonames server. Geonames is an awesome service. However, sometimes > Geonames is swamped with requests and then we don't get timezones (we > could opt for a more stable paid subscription, but we don have any > money to invest here). New followers then are left with UTC as their > default timezone, which leads to confusion." > > "Also, sending requests to Geonames all the time causes a lot of data > traffic. We would like to cut on our diet of data traffic." > > "So, we would like to figure out ourselves which timezone to use for > certain coordinates. From what we gather, this is not impossible. It > takes a map with the timezones of the world as polygons and a script > to find out in which polygon a set of coordinates lies.:" > --- > > It occurs to me that because OSM uses GeoNames that this would improve > the chances of OSM requests succeeding, so everyone benefits. For > further details see the link above. > > Once again, I am just a user of their service, I have no connection at > all with TWISST.
Checking if a point is inside a polygons is trivial, but is it what they really want? Wouldn't just the longitude tell you the time better than the timezone? E.g. offset_from_gmt = ((lon - 180) / 15) hours Cheers _______________________________________________ dev mailing list [email protected] http://lists.openstreetmap.org/listinfo/dev
