Finds the nth weekday of a given month and year

nthdayofmonth.R

nthdayofmonth <- function(year, month, day, nth = 1){
        #' Finds the nth weekday of a given month and year  
        #' 
        #' Enter the year or years, month, and weekday along with the nth
        #' weekday of the month you are interested in. 
        #' 
        #' @param year Character Vector. Year/s of interest  
        #' @param month Character. The numeric month i.e. "11" for November  
        #' @param day Character. The full weekday of interest, will do partial
        #' matching.  
        #' @param nth numeric. The cardinality of the weekday of interest. eg.
        #' nth = 2 with day = "Tuesday" mean the 2nd Tuesday of the month.  
        #' 
        #' @return A character vector of dates 
        day <- match.arg(day, c("Sunday", "Monday", "Tuesday", 
                                "Wednesday", "Thursday", 
                                "Friday", "Saturday"))
        datestring <- paste(year, month, "01", sep = "-")
        datestart <- as.Date(datestring)
        x <- sapply(datestart, function(x){
                datevec <- seq(x, by = 1, length.out = nth * 7)
                match <- datevec[format(datevec, "%A") == day & format(datevec, "%m") == month][nth]
        })
        out <- as.Date(unlist(x), origin = "1970-01-01")
        return(out)
}