Hi, I have to deal with time-stamped data coming from outside my own time zone, so the problem is likely poor knowledge of European time zones on my part. But I am puzzled just the same.
I thought that setting a time zone of "Europe/Copenhagen" would be the same as "CET" in winter and "CEST" in summer. This test in winter works as expected: > a = as.POSIXct("2013-02-25 01:00:00", tz="Europe/Copenhagen"); a [1] "2013-02-25 01:00:00 CET" > b = as.POSIXct("2013-02-25 01:00:00", tz="CET"); b [1] "2013-02-25 01:00:00 CET" > a-b Time difference of 0 secs But this one is summer does not work as I expected: > c = as.POSIXct("2013-07-25 01:00:00", tz="Europe/Copenhagen"); c [1] "2013-07-25 01:00:00 CEST" > d = as.POSIXct("2013-07-25 01:00:00", tz="CEST"); d [1] "2013-07-25 01:00:00 UTC" > e = as.POSIXct("2013-07-25 01:00:00", tz="CET"); e [1] "2013-07-25 01:00:00 CEST" > c-d Time difference of -2 hours > c-e Time difference of 0 secs Setting tz to "Europe/Copenhagen" in summer in c first appears to be the same as setting it to "CEST" because the output is showing "CEST". But d should then be the same as c, and it is not. What is happening? Thanks in advance, Denis Chabot ______________________________________________ R-help@r-project.org mailing list 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.