[R] POSIX time zone codes
Prof Brian Ripley
ripley at stats.ox.ac.uk
Thu Mar 9 12:18:56 CET 2006
On Tue, 7 Mar 2006, Jason Horn wrote:
> Thank you again Gabor, that did the trick. Any thoughts on where I
> go go for a reference for these time codes? Where did you get
> "CDT6CST" from? Or is this just one of those things that is "common
> knowledge" in UNIX circles.
> To the R developers: I recommend a sentence be added to the manual
> for as.POSIXxx such as "vales for tz are system dependent, examples
> for common systems are....."
You mean repeating what is already there:
tz: A timezone specification to be used for the conversion, _if
one is required_. System-specific, but '""' is the current
timezone, and '"GMT"' is UTC (Coordinated Universal Time, in
? What are `common systems'?
If you have access to such a set of systems and can provide a
comprehensive set of (tested) examples please provide a patch. The POSIX
specification is at
You are expecting R to give you information about your OS, and that's
an unreasonable expectation.
> On Mar 7, 2006, at 9:00 AM, Gabor Grothendieck wrote:
>> Only "" and "GMT" are really guaranteed to work on all systems
>> since the time zones are system dependent but try: "CDT6CST"
>> and see if that works on your system.
>> On 3/7/06, Jason Horn <jhorn at bu.edu> wrote:
>>> as.POSIX(x, tz="UTC") ... works, gives UTC times
>>> as.POSIX(x, tz="EST") ... works, gives EST times
>>> as.POSIX(x, tz="CST") ... does NOT work, gives UTC times
>>> On Mar 7, 2006, at 8:05 AM, Jason Horn wrote:
>>>> as.POSIX(x, tz="UTC") ... works, gives UTC times
>>>> as.POSIX(x, tz="UTC") ... works, gives EST times
>>>> as.POSIX(x, tz="CST") ... does NOT work, gives UTC times
Brian D. Ripley, ripley at stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
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