Argthtjtr

I am using "R" to format a character variable that has two different kinds of date formats (MM-DD-YYYY & YYYY-MM-DD). The second is an excel origin date.

DateVar <- c("12-07-2017", "43229", "43137", "03-27-2018")

I created vector using grepl to identify both types and then a for loop to apply the as.date function to only the "excel origin dates".

indicator <- !grepl("-", DateVar)



for(i in indicator == TRUE){

as.date(DateVar, origin = "1899-12-30") 

It is not working for me however, so I am looking if someone can point me in the right direction.

Thanks.

Couple of things: The for loop is unnecessary - just subset DateVar with [indicator]. Second, it's as.Date, not as.date (note the "D"). Third, since it's a character vector, you need to pass the origin numbers through as.integer for as.Date to be able to work with them:

as.Date(as.integer(DateVar[indicator]), origin = "1899-12-30")

(or, without the intervening indicator assignment:

as.Date(as.integer(DateVar[!grepl("-",DateVar)]), origin = "1899-12-30")



[1] "2018-05-09" "2018-02-06"

If you wish to input these dates back into DateVar, you again use the subset function:

DateVar[indicator]<-format(as.Date(as.integer(DateVar[indicator]), origin = "1899-12-30"), "%m-%d-%Y")