Re: [Rd] Date conversion with as.POSIXct and as.POSIXlt (PR#9196)

From: Gabor Grothendieck <ggrothendieck_at_gmail.com>
Date: Fri 01 Sep 2006 - 10:25:36 GMT

Note that there is some discussion in the help desk article in R News 4/1 and a table of tested conversions at the end of that article. If x is of class "Date" then for converting from Date to POSIXct the table suggests as.POSIXct(format(x)) or as.POSIXct(format(x), tz = "GMT") according to whether you want the current time zone or GMT.

On 9/1/06, erich.neuwirth@univie.ac.at <erich.neuwirth@univie.ac.at> wrote:
> Full_Name: Erich Neuwirth
> Version: 2.3.1
> OS: Windows XP, Linux
> Submission from: (NULL) (131.130.135.167)
>
>
> Converting Sys.Date() to a POSIX compliant time type in different ways
> produces inconsistent results:
> > Sys.date()
> [1] "2006-09-01"
> > as.POSIXct(Sys.Date())
> [1] "2006-09-01 02:00:00 CEST"
> > as.POSIXlt(Sys.Date())
> [1] "2006-09-01"
> > as.POSIXct(as.POSIXlt(Sys.Date()))
> [1] "2006-09-01 01:00:00 CEST"
>
> Applying as.POSIXct directly or first applying as.POSIXlt and then
> applying as.POSIXct produces different results.
>
> This happens on Linux with timezone "CEST"
> > Sys.time()
> [1] "2006-09-01 11:03:36 CEST"
> and on Windows with timezone "W. Europe Daylight Time"
> > Sys.time()
> [1] "2006-09-01 11:11:15 W. Europe Daylight Time"
>
> ______________________________________________
> R-devel@r-project.org mailing list
>
https://stat.ethz.ch/mailman/listinfo/r-devel
>



R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel Received on Fri Sep 01 20:27:47 2006

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.1.8, at Wed 06 Sep 2006 - 11:39:09 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-devel. Please read the posting guide before posting to the list.