library(zoo) ?yearmon library(chron) ?month.day.year
?strptime See R News 4/1. On Wed, Apr 23, 2008 at 6:13 AM, Worik R <[EMAIL PROTECTED]> wrote: > I am a bit worried I am reinventing the wheel. Isn't there a calendar > system in R? > > I have written a function to add months to a date and return the number of > days resulting. I am newish to R so I am hoping there is a package that > can do this sort of date arithmetic for me... > > Worik > > DaysInMonths <- function(s,d){ > ## Days in d months from s > sdate <- MSTD(s) > > ## Get day, month and the year > sd <- as.double(days(sdate)) > sm <- as.double(months(sdate)) > sy <- as.double.difftime(years(sdate)) > > sm <- sm+d > while(sm > 12){ > sm <- sm-12 > sy <- sy+1 > } > sdate2 <- MSTD(paste(sd,sm,sy,sep="/")) > return(as.double(difftime(sdate2, sdate, units="days"))) > } > > MSTD <- function(a){ > if(class(a)[1] == "dates") return (a) > return(dates(a, format="d/m/y")) > } > > [[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.