Hello, sorry for my mail yesterday about the POSIXct problems. I was a bit tired and now I found out the real problem. When importing time data over a daylight saving time shift, R shifts two times. I don't now whether it is a bug or a (wrongly used) feature
If you execute the following code: -------------- test<-c("31/03/2002 0:00", "31/03/2002 0:15", "31/03/2002 0:30", "31/03/2002 0:45", "31/03/2002 1:00", "31/03/2002 1:15", "31/03/2002 1:30", "31/03/2002 1:45", "31/03/2002 2:00", "31/03/2002 2:15", "31/03/2002 2:30", "31/03/2002 2:45", "31/03/2002 3:00", "31/03/2002 3:15", "31/03/2002 3:30", "31/03/2002 3:45", "31/03/2002 4:00", "31/03/2002 4:15", "31/03/2002 4:30", "31/03/2002 4:45", "31/03/2002 5:00", "31/03/2002 5:15", "31/03/2002 5:30", "31/03/2002 5:45", "31/03/2002 6:00"); timetest<-strptime(as.character(test), format = "%d/%m/%Y %H:%M"); timetest2<-as.POSIXct(timetest); -------------- then R 1.7.0 gives on my Mandrake 9.1: > test [1] "31/03/2002 0:00" "31/03/2002 0:15" "31/03/2002 0:30" "31/03/2002 0:45" [5] "31/03/2002 1:00" "31/03/2002 1:15" "31/03/2002 1:30" "31/03/2002 1:45" [9] "31/03/2002 2:00" "31/03/2002 2:15" "31/03/2002 2:30" "31/03/2002 2:45" [13] "31/03/2002 3:00" "31/03/2002 3:15" "31/03/2002 3:30" "31/03/2002 3:45" [17] "31/03/2002 4:00" "31/03/2002 4:15" "31/03/2002 4:30" "31/03/2002 4:45" [21] "31/03/2002 5:00" "31/03/2002 5:15" "31/03/2002 5:30" "31/03/2002 5:45" [25] "31/03/2002 6:00" > > timetest [1] "2002-03-31 00:00:00" "2002-03-31 00:15:00" "2002-03-31 00:30:00" [4] "2002-03-31 00:45:00" "2002-03-31 01:00:00" "2002-03-31 01:15:00" [7] "2002-03-31 01:30:00" "2002-03-31 01:45:00" "2002-03-31 03:00:00" [10] "2002-03-31 03:15:00" "2002-03-31 03:30:00" "2002-03-31 03:45:00" [13] "2002-03-31 03:00:00" "2002-03-31 03:15:00" "2002-03-31 03:30:00" [16] "2002-03-31 03:45:00" "2002-03-31 04:00:00" "2002-03-31 04:15:00" [19] "2002-03-31 04:30:00" "2002-03-31 04:45:00" "2002-03-31 05:00:00" [22] "2002-03-31 05:15:00" "2002-03-31 05:30:00" "2002-03-31 05:45:00" [25] "2002-03-31 06:00:00" > > timetest2 [1] "2002-03-31 00:00:00 CET" "2002-03-31 00:15:00 CET" [3] "2002-03-31 00:30:00 CET" "2002-03-31 00:45:00 CET" [5] "2002-03-31 01:00:00 CET" "2002-03-31 01:15:00 CET" [7] "2002-03-31 01:30:00 CET" "2002-03-31 01:45:00 CET" [9] "2002-03-31 03:00:00 CEST" "2002-03-31 03:15:00 CEST" [11] "2002-03-31 03:30:00 CEST" "2002-03-31 03:45:00 CEST" [13] "2002-03-31 03:00:00 CEST" "2002-03-31 03:15:00 CEST" [15] "2002-03-31 03:30:00 CEST" "2002-03-31 03:45:00 CEST" [17] "2002-03-31 04:00:00 CEST" "2002-03-31 04:15:00 CEST" [19] "2002-03-31 04:30:00 CEST" "2002-03-31 04:45:00 CEST" [21] "2002-03-31 05:00:00 CEST" "2002-03-31 05:15:00 CEST" [23] "2002-03-31 05:30:00 CEST" "2002-03-31 05:45:00 CEST" [25] "2002-03-31 06:00:00 CEST" There is a clear time shift timetest[8] and timetest[9] and another one between timetest[12] and timetest[13]. I.e. timetest[9:12] are wrongly converted. In october (reverse timeshift in daylight time) there is no shift at all. It seems that it was a feature before that has been badly patched. I'm using R 1.7.0 on Mandrake Linux in Belgium (CEST?) It does not occur on my MacOSX box (both Darwin and Carbon version); I don't now about the windows version. Thanks, Wouter Buytaert ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help