[R] Incorrect DST time changes in DateTimeClasses

[Andrew Digby]

Apologies - I intended to add that info at the end: OS X 10.8.2 and R 2.15.1.

Many thanks.

> R.Version()
$platform
[1] "x86_64-apple-darwin9.8.0"
$arch
[1] "x86_64"
$os
[1] "darwin9.8.0"
$system
[1] "x86_64, darwin9.8.0"
$status
[1] ""
$major
[1] "2"
$minor
[1] "15.1"
$year
[1] "2012"
$month
[1] "06"
$day
[1] "22"
$`svn rev`
[1] "59600"
$language
[1] "R"
$version.string
[1] "R version 2.15.1 (2012-06-22)"
$nickname
[1] "Roasted Marshmallows"


On 7/12/2012, at 04:29 , Uwe Ligges <ligges at statistik.tu-dortmund.de> wrote:

> 
> 
> On 06.12.2012 15:54, Jeff Newmiller wrote:
>> What OS are you using? It makes a difference.
> 
> ... and R version.
> 
> Uwe Ligges
> 
>> ---------------------------------------------------------------------------
>> Jeff Newmiller                        The     .....       .....  Go Live...
>> DCN:<jdnewmil at 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.
>> 
>> Andrew Digby <andrewdigby at mac.com> wrote:
>> 
>>> 
>>> Can anyone please shed any light on why R DateTimeClasses give weird
>>> times for when daylight saving time information changes, and which
>>> aren't consistent with the OS?
>>> 
>>> Example:
>>> 
>>> 	Expected result: in New Zealand DST stopped (NZDT -> NZST) at 03:00
>>> NZDT on 2010-04-04, as confirmed by the OS time zone info (OS X
>>> 10.8.2):
>>> 
>>> 	zdump -v /etc/localtime
>>> 		/etc/localtime  Sat Apr  3 13:59:59 2010 UTC = Sun Apr  4 02:59:59
>>> 2010 NZDT isdst=1
>>> 		/etc/localtime  Sat Apr  3 14:00:00 2010 UTC = Sun Apr  4 02:00:00
>>> 2010 NZST isdst=0
>>> 
>>> 	Result in R: R has DST changing at 02:26:08, instead of 03:00!
>>> 
>>> 	> a<-as.POSIXlt('2010-04-04 02:26:07',tz="NZ")
>>> 	> a$isdst
>>> 	[1] 1
>>> 	> b<-as.POSIXlt('2010-04-04 02:26:08',tz="NZ")
>>> 	> b$isdst
>>> 	[1] 0
>>> 
>>> 
>>> So does R get its DST information from somewhere else? Any suggestions
>>> would be much appreciated!
>>> 
>>> Thanks
>>> 
>>> 	[[alternative HTML version deleted]]
>>> 
>>> ______________________________________________
>>> R-help at 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 at 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.
>>