[R] Incrementing Dates

[Dirk Eddelbuettel]

On Wed, Apr 23, 2008 at 12:17:55PM +1200, Worik R wrote:
> How can I increment the value of a Date class?
> 
> I want to add a day, month or year to a date.

As the shoe company from Portland would say, "just do it".  The key is
knowing that the seq() function has a variant operating on the Date
class:

> today <- Sys.Date()
> today
[1] "2008-04-22"
> args(seq.Date)
function (from, to, by, length.out = NULL, along.with = NULL, 
    ...) 
NULL
> seq(today, by="month", length=1)
[1] "2008-04-22"
> seq(today, by="month", length=2)
[1] "2008-04-22" "2008-05-22"
> seq(today, by="week", length=2)
[1] "2008-04-22" "2008-04-29"
> seq(today, by="day", length=2)
[1] "2008-04-22" "2008-04-23"
> 

Dirk


-- 
Three out of two people have difficulties with fractions.