It really depends on what you want to do with them but one possibility might be to represent them as chron dates and use a time of 0 for true dates and noon for missing dates replacing the missing day with 01 or 15 or some other day:
> library(chron) > x <- c("01/00/05", "01/22/06") > no.day <- regexpr("/00/", x) > 0 > as.chron(ifelse(no.day, sub("/00/", "/15/", x), x )) + no.day/2 [1] (01/15/05 12:00:00) (01/22/06 00:00:00) We can then tell which have the incomplete dates with as.numeric(xx) %% 1 > 0 On Sun, Feb 24, 2008 at 9:00 PM, Anupa Fabian <[EMAIL PROTECTED]> wrote: > I have a data frame which contains some valuable date information. But for a > few of the dates, the day information missing . > > Viz: > > interesting.data$date > [1] "1/22/93" "1/22/93" "1/23/93" "1/00/93" "1/28/93" "1/31/93" "1/12/93" > > i.e. for dates where the day info is missing, the "%d" part of the > "%m/%d/%yy" format is simply represented as "00". > > When I apply as.Date to the date information, the dates which don't contain > exact day information are converted to "NA". > > Viz: > > as.Date(interesting.data$date) > [1] "1993-01-22" "1993-01-22" "1993-01-23" NA "1993-01-28" "1993-01-31" > "1993-01-12" > > Is there a way of using the as.Date function when I only have partial dates > (eg missing day information which is represented as "00", as above) such > that the date isn't represented as NA? > > Thanks, > Anupa > > > > > > > > > ____________________________________________________________________________________ > Never miss a thing. Make Yahoo your home page. > > [[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. > ______________________________________________ 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.