If you make no further assumptions then this question is not solvable. For example we use standard time in our data collection systems even though legal time here applies daylight savings offset in the summer. In some cases I have seen data collected from sites in multiple time zones recorded in one data base with a single time zone. Even if you do assume local legal time applies in all cases, the boundaries of the time zones have changed over time. There exist time zone maps (e.g. http://efele.net/maps/tz/world/) that you could assume apply but I am not aware of any in CRAN. Someone on r-sig-geo might be able to help. --------------------------------------------------------------------------- Jeff Newmiller The ..... ..... Go Live... DCN:<jdnew...@dcn.davis.ca.us> Basics: ##.#. ##.#. Live Go... Live: OO#.. Dead: OO#.. Playing Research Engineer (Solar/Batteries O.O#. #.O#. with /Software/Embedded Controllers) .OO#. .OO#. rocks...1k --------------------------------------------------------------------------- Sent from my phone. Please excuse my brevity.
carlisle thacker <carlisle.thac...@gmail.com> wrote: >I have data that provide longitude, latitude, and local date and time >but >no information about the corresponding time zone. How to identify the >time >zone so they can be converted to a common date/time? > >Thanks, > >Carlisle > > [[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. ______________________________________________ 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.