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

[Jeff Newmiller]

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_DE.UTF-8;LC_IDENTIFICATION=C"
>
>Any Idea?
>
>Best regards
>Tilmann
>
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-- 
Sent from my phone. Please excuse my brevity.