Is there a shorter way to extract a date from a string?

Question

I wrote code to extract the date from a given string. Given

  > \"Date: 2012-07-29, 12:59AM PDT\"

it extracts

  > \"         


        

Answer 1

Regex with backreferencing works:

> sub("^.+([0-9][0-9][0-9][0-9]-[0-9][0-9]-[0-9][0-9]).+$","\\1","Date: 2012-07-29, 12:59AM PDT")
[1] "2012-07-29"

But @Dirk is right that parsing it as a date is the right way to go.