[R] Addition of numeric data to dates

[Prof Brian Ripley]

On Fri, 14 Mar 2008, Henrique Dallazuanna wrote:

> If I understand:
>
> as.Date("2008-03-14") + 5*365

What about leap years?  That is 2013-03-13.

> x <- as.Date("2008-03-14")
> xx <- as.POSIXlt(x)
> xx$year <- xx$year+5
> as.Date(xx)
[1] "2013-03-14"

is I think what is being asked for.

> On 14/03/2008, Jillywadd <jill.waddingham07 at imperial.ac.uk> wrote:
>>
>>  I currently have a table of data with a column of start dates and a column
>>  with some numbers representing years. I need to add these numbers to the
>>  dates to get an end date. The two types of data are obviously incompatible
>>  and adddition of the two will not work. Does anyone know how I might go
>>  about this?? %-|

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
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