rdate

How do I find the first and last day of next month?

If I have a given date, how do I find the first and last days of the next month?

For example,

today <- as.Date("2009-04-04")

I want to find

# first date in next month
"2009-05-01"  

# last date in next month
"2009-05-31"
Solution

  • You can do this with base R:

    today <- as.Date("2009-04-04")

first <- function(x) {
  x <- as.POSIXlt(x)
  x$mon[] <- x$mon + 1
  x$mday[] <- 1
  x$isdst[] <- -1L
  as.Date(x)
}

first(today)
#[1] "2009-05-01"

first(first(today)) - 1
#[1] "2009-05-31"