[R] Date Time, as.POSIXct used locale, strange plot behavior

[PIKAL Petr]

Hi.

It should be probably CET not CEST.

arrows(as.POSIXct("2021-04-21 00:00:00", tz="CEST"),
       0.3,
       as.POSIXct("2021-04-21 00:00:00", tz="CEST"),
       0.2,
       length=0.07, angle=15)


arrows(as.POSIXct("2021-04-21 00:00:00", tz="CET"),
       0.3,
       as.POSIXct("2021-04-21 00:00:00", tz="CET"),
       0.2,
       length=0.07, angle=15)

Cheers
Petr

> -----Original Message-----
> From: R-help <r-help-bounces using r-project.org> On Behalf Of Jeff Newmiller
> Sent: Thursday, April 29, 2021 11:20 PM
> To: r-help using r-project.org; Tilmann Faul <Tilmann_Faul using t-online.de>
> Subject: Re: [R] Date Time, as.POSIXct used locale, strange plot behavior
> 
> What is your TZ environment variable set to? That's what time conversion
> defaults to  ?DateTimeClasses
> 
> Also, I am not sure CEST is a valid timezone designation... it can be
system
> dependent, but using one of the elements listed in ?OlsonNames.
> 
> On April 29, 2021 12:22:44 PM PDT, Tilmann Faul <Tilmann_Faul using t-online.de>
> wrote:
> >Hy,
> >
> >stumbled over the following problem while plotting DateTime Objects.
> >
> >plot(as.POSIXct(c("2021-04-21 00:00:00", "2021-04-21 23:59:59")), c(0,
> >1), type='l')
> >
> >arrows(as.POSIXct("2021-04-21 00:00:00", tz="CEST"),
> >       0.3,
> >       as.POSIXct("2021-04-21 00:00:00", tz="CEST"),
> >       0.2,
> >       length=0.07, angle=15)
> >
> ># arrow at 02:00, why?
> >
> >arrows(as.POSIXct("2021-04-21 00:00:00"),
> >       0.3,
> >       as.POSIXct("2021-04-21 00:00:00"),
> >       0.2,
> >       length=0.07, angle=15, col='red')
> >
> ># arrow at 00:00 as expected
> >
> >as.POSIXct(c("2021-04-21 00:00:00", "2021-04-21 23:59:59"))[1] # [1]
> >"2021-04-21 CEST"
> >as.POSIXct("2021-04-21 00:00:00", tz="CEST") # [1] "2021-04-21 CEST"
> >as.POSIXct("2021-04-21 00:00:00")
> ># [1] "2021-04-21 CEST"
> >
> >all representations on my system are the same, why is the plot location
> >of the arrows different??
> >I am located in Germany, my locale:
> >Sys.getlocale()
> >[1]
> >"LC_CTYPE=de_DE.UTF-8;LC_NUMERIC=C;LC_TIME=de_DE.UTF-
> 8;LC_COLLATE=de_DE.UTF-8;LC_MONETARY=de_DE.UTF-
> 8;LC_MESSAGES=de_DE.UTF-8;LC_PAPER=de_DE.UTF-
> 8;LC_NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=de_D
> E.UTF-8;LC_IDENTIFICATION=C"
> >
> >Any Idea?
> >
> >Best regards
> >Tilmann
> >
> >______________________________________________
> >R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> >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.
> 
> --
> Sent from my phone. Please excuse my brevity.
> 
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.