Hi. I am new to POSIX and I'd like to understand the reason of this difference.
dt1 = as.POSIXct("2014-03-29 09.00", format="%Y-%m-%d %H.%M") dt2 = as.POSIXct("2014-03-30 09.00", format="%Y-%m-%d %H.%M") dt2-dt1 > dt1[1] "2014-03-29 09:00:00 CET"> dt2[1] "2014-03-30 09:00:00 CEST"> dt2-dt1 Time difference of 23 hours This is right, because on Mar 31 at 2 PM we jump directly to 3PM, DST. On the contrary, I don't understand the following: dt1 = as.POSIXct("2014-04-18 09.00", format="%Y-%m-%d %H.%M", tz = "CEST") dt2 = as.POSIXct("2014-04-18 09.00", format="%Y-%m-%d %H.%M", tz = "GMT") > dt1[1] "2014-04-18 09:00:00 CEST"> dt2[1] "2014-04-18 09:00:00 GMT"> > dt1-dt2Time difference of 0 secs I should expected a time difference of 2 hours, as CEST is GMT+2. Anyone can help me? Thank you, Nicola [[alternative HTML version deleted]] ______________________________________________ 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.