I may have misunderstood your question. vec1 <- seq(as.POSIXct("2009-01-01 00:00:00",format="%Y-%m-%d %H:%M:%S"),by= '12 hour', length=12)
vec1[1:3] #returns with time zone #[1] "2009-01-01 00:00:00 EST" "2009-01-01 12:00:00 EST" #[3] "2009-01-02 00:00:00 EST" If you don't want the time zone info:, strftime(vec1,usetz=FALSE)[1:2] #[1] "2009-01-01 00:00:00" "2009-01-01 12:00:00" Also, you can change the time zone, Sys.setenv(TZ="GMT") vec1[1:2] #[1] "2009-01-01 05:00:00 GMT" "2009-01-01 17:00:00 GMT" It is not clear what you want. A.K. I have a date from which returns head(mt, 3) DateW | Date |tempDeg 2 2009-01-01 01:00:00 | 2009-01-01 01:00:00 | -23.6 3 2009-01-01 02:00:00 | 2009-01-01 02:00:00 | -25.7 4 2009-01-01 03:00:00 | 2009-01-01 03:00:00 | -26.5 Why does this return a time with MST? mt[1,2] [1] "2009-01-01 01:00:00 MST" ______________________________________________ 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.