days and years are from the chron package and operate on chron objects, not POSIXlt objects.
If you have a POSIXlt object, EDATE, you can get the years and julian day of the year like this: as.numeric(format(EDATE,"%Y")) as.numeric(format(EDATE,"%j")) See ?strptime for those % codes and many others. Alternately you can convert your dates to chron objects instead of POSIXlt objects and then you can use years and days as you did below. See the chron package for that. --- Date: Mon, 8 Mar 2004 15:50:01 +0100 From: Christian Schulz <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Subject: [R] years from as.POSIXlt Hi, how it's possible to extract the year and the number of days from Julian date. i'm little confused about the last two functions and ?years . EDATE comes from sqlQuery with as.is=T EDATE <- as.POSIXlt(datvears$ENROLLDAY) Many thanks, Christian > EDATE[1:5] [1] "2000-06-30 11:25:01" "2000-06-30 11:39:55" "2000-06-30 12:11:11" [4] "2000-06-30 12:13:32" "2000-06-30 12:50:12" > weekdays(EDATE[1:5]) [1] "Freitag" "Freitag" "Freitag" "Freitag" "Freitag" > months(EDATE[1:5]) [1] "Juni" "Juni" "Juni" "Juni" "Juni" > years(EDATE[1:5]) NULL > days(EDATE[1:5]) NULL > ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
