[R] time zones from longitude, latitude, and date

[Jeff Newmiller]

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.
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Sent from my phone. Please excuse my brevity.

carlisle thacker <carlisle.thacker at 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
>
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