On Sat, Apr 25, 2020 at 10:41 AM Johannes Ranke <johannes.ra...@jrwb.de> wrote: > > Am Samstag, 25. April 2020, 01:02:38 CEST schrieb Jeroen Ooms: > > Hi all, > > > > I am testing R 4.0 and ran into an issue with timezones on Ubuntu > > Focal: converting a timestamp to another timezone results in NA: > > > > as.POSIXct(as.POSIXlt(Sys.time(), tz = "CET"), tz = "EST") > > > > This only happens on Ubuntu Focal, it seems to work fine on Ubuntu > > Bionic. I am the standard ubuntu docker image icw/ r-base from Dirk's > > ppa:edd/r-4.0 on both systems. > > works fine using the backported R 4.0.0 on Debian buster: > > R> as.POSIXct(as.POSIXlt(Sys.time(), tz = "CET"), tz = "EST") > [1] "2020-04-25 10:05:29 EST"
Perhaps the root cause of the change in behavior is that on the focal/bullseye docker images, /usr/bin/timedatectl exists, but it does not work: root@focal:/# timedatectl System has not been booted with systemd as init system (PID 1). Can't operate. Failed to create bus connection: Host is down R assumes that if it timedatectl exists, it can be used. On the docker image of bionic and buster, timedatectl simply is not installed so R does not call it. The consequence though, is very subtle changes in behavior of time conversion edge cases that I cannot explain. For example we get differences between "UTC" and "Etc/UTC": > Sys.timezone() [1] "Etc/UTC" # System has not been booted with systemd as init system (PID 1). Can't operate. # Failed to create bus connection: Host is down Warning message: In system("timedatectl", intern = TRUE) : running command 'timedatectl' had status 1 as.POSIXct(strptime("24.04.2020 01:00", format = "%d.%m.%Y %H:%M", tz = "CET"), tz = "") [1] NA as.POSIXct(strptime("24.04.2020 01:00", format = "%d.%m.%Y %H:%M", tz = "CEST"), tz = "") [1] "2020-04-24 01:00:00 UTC" > as.POSIXct(strptime("24.04.2020 01:00", format = "%d.%m.%Y %H:%M", tz = > "CET"), tz = "Etc/UTC") [1] NA > as.POSIXct(strptime("24.04.2020 01:00", format = "%d.%m.%Y %H:%M", tz = > "CET"), tz = "UTC") [1] "2020-04-24 01:00:00 UTC" _______________________________________________ R-SIG-Debian mailing list R-SIG-Debian@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-debian