[R-pkg-devel] Surprised by as.Date() and lubridate::today()

[Duncan Murdoch]

On 19/06/2017 5:44 PM, Pedro J. Aphalo wrote:
> Hello,
>
> I was surprised first by the behaviour of lubridate::today(), and when I
> investigated further, by the behaviour of as.Date.POSIXlt(). Some
> examples follow:

You've written to the wrong place.  This list is for package developers.

If you think there's a problem in lubridate, you should write to its 
maintainer, which maintainer("lubridate") says is "Vitalie Spinu 
<spinuvit at gmail.com>".

If you think there's a problem with as.Date.POSIXlt, you should confirm 
that it happens in a clean session (lubridate might have replaced it), 
then report on the bug list, or on R-devel.

Duncan Murdoch

>
> library(lubridate)
> # today() does not behave as I expected
> tz(now(tzone = "EET"))
> tz(today(tzone = "EET")) # UTC!!
> today("America/New_York") == today("Asia/Tokyo") # FALSE with no warning
> (lack of warning is wrong?).
> tz(today("America/New_York")) # UTC!
> tz(today("Asia/Tokyo")) # UTC!
> ymd("2017-06-19", tz = "America/New_York") == ymd("2017-06-20", tz =
> "Asia/Tokyo") # FALSE with warning.
> tz(ymd("2017-06-19", tz = "America/New_York")) # OK
> tz(ymd("2017-06-20", tz = "Asia/Tokyo")) # OK
>
> # nothing unusual here
> tz(as.POSIXlt(now(), tz = "EET"))
> tz(as.POSIXlt(now(tzone = "EET")))
> tz(as.POSIXlt(now(tzone = "EET"), tz = "EET"))
> # but the unexpected seems to be the behaviour of as.Date.POSIXlt() as
> all returned values have tz set to "UTC"
> tz(as.Date(as.POSIXlt(now())))  # UTC!!
> tz(as.Date(as.POSIXlt(now(tzone = "EET"), tz = "EET"), tz = "EET"))  # UTC!!
> tz(as.Date(as.POSIXlt(now(), tz = "EET"), tz = "EET"))  # UTC!!
> tz(as.Date(as.POSIXlt(now()), tz = "EET"))  # UTC!!
>
> Is this as expected? (R 3.4.0 Windows 10 64, and R 3.3.3, with lubridate
> 1.6.0)
>
> Thanks in advance for any insight.
>
> Best regards,
>
> Pedro.
>