[R] Adding a year to existing date

[MacQueen, Don]

Here is an example that could probably be described as "adding a year":

dates <- c('2008-01-01','2009-03-02')
tmp <- as.POSIXlt(dates)tmp$year <- tmp$year+1
dates2 <- format(tmp)
> dates
[1] "2008-01-01" "2009-03-02"
> dates2
[1] "2009-01-01" "2010-03-02"

## to begin to understand how it works, give the command
##   unclass(tmp)
## (and read the help pages
##   ?as.POSIXlt
##   ?DateTimeClasses

Another example:

dates <- as.Date(c('2008-01-01','2009-03-02'))
tmp <- as.POSIXlt(dates)
tmp$year <- tmp$year+1
dates2 <- as.Date(tmp)



##   ?as.Date
##   ?Date




-Don


-- 
Don MacQueen

Lawrence Livermore National Laboratory
7000 East Ave., L-627
Livermore, CA 94550
925-423-1062





On 11/16/11 8:33 PM, "arunkumar1111" <akpbond007 at gmail.com> wrote:

>Hi 
>
> I need to add an year to and date field in the dataframe.
>
>Please help me
>
>X Date
>1 2008-01-01
>2 2008-02-01
>3 2003-03-01
>
>
>Thanks in advance
>
>--
>View this message in context:
>http://r.789695.n4.nabble.com/Adding-a-year-to-existing-date-tp4078930p407
>8930.html
>Sent from the R help mailing list archive at Nabble.com.
>
>______________________________________________
>R-help at 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.