Thanks. This seems to return the correct offset. For example, it knows about the time zone not following the meridian in this part of the Pacific:
> GNtimezone(14,-172) rawOffset dstOffset gmtOffset lng lat 1 -11 0 -11 -172 14 Warning message: In readLines(u) : incomplete final line found on ' http://ws.geonames.org/timezoneJSON?lat=14&lng=-172' > GNtimezone(24,-172) rawOffset dstOffset gmtOffset lng lat 1 -10 0 -10 -172 24 Warning message: In readLines(u) : incomplete final line found on ' http://ws.geonames.org/timezoneJSON?lat=24&lng=-172' > GNtimezone(34,-172) rawOffset dstOffset gmtOffset lng lat 1 -11 0 -11 -172 34 Warning message: In readLines(u) : incomplete final line found on ' http://ws.geonames.org/timezoneJSON?lat=34&lng=-172' Too bad it doesn't accept vectors of coordinates. > GNtimezone(c(14,24,34),c(-172,-172,-172)) rawOffset dstOffset gmtOffset lng lat 1 -11 0 -11 -172 14 Warning message: In readLines(u) : incomplete final line found on ' http://ws.geonames.org/timezoneJSON?lat=14&lng=-172' How to get daylight time? Regards, Carlisle On Mon, Sep 23, 2013 at 3:26 PM, David Winsemius <dwinsem...@comcast.net>wrote: > > On Sep 23, 2013, at 9:05 AM, carlisle thacker wrote: > > Gabor, > > Thanks for your tip about zone.tab. It provides country codes and lat/lon > of the zone's principal location, which while useful is not exactly what I > need. I would like to know the coordinates of time zone boundaries. > Better still would be a function, which returns the name of the time zone > in which given lat/lon is situated. > > For example, in which time zone is 22N,166W? And at what times of year > might daylight savings time be in effect? > > > From the posting from Olivier Eterradossi: > > library(geonames) > GNtimezone(22,166) > #---------------- > Loading required package: rjson > rawOffset dstOffset gmtOffset lng lat > 1 11 0 11 166 22 > Warning message: > In readLines(u) : > incomplete final line found on ' > http://ws.geonames.org/timezoneJSON?lat=22&lng=166' > > So it looks like the middle of the Pacific (GMT-11) near Hawaii. Seems a > reasonable result. > > -- > David > > > > Regards, > > Carlisle > > > On Sat, Sep 21, 2013 at 3:17 AM, Gabor Grothendieck < > ggrothendi...@gmail.com> wrote: > >> On Fri, Sep 20, 2013 at 4:31 PM, carlisle thacker >> <carlisle.thac...@gmail.com> wrote: >> > I was looking for something like shown on the map: >> > >> http://upload.wikimedia.org/wikipedia/commons/8/88/World_Time_Zones_Map.png >> > >> > Information about local daylight savings times would also help. >> > >> > The data are from ships, supposedly in local time, but no time-zone >> info is >> > given. A function that would return time zone and whether or not >> daylight >> > savings time applies at given date would would help. I'm trying to >> track >> > down more information about the data and whether they can be referenced >> to >> > UTC. >> >> The zone.tab file has this information. See the Examples section at >> the end of ?Sys.timezone for info on its whereabouts. >> > > > David Winsemius, MD > Alameda, CA, USA > > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
