title: Splitting Columns by Number of Characters
body: <p>I have a column of dates in a data table entered in 6-digit numbers as such: <code>201401, 201402, 201403, 201412, etc.</code> where the first 4 digits are the year and second two digits are month.</p>
  
  <p>I'm trying to split that column into two columns, one called "year" and one called "month". Been messing around with <code>strsplit()</code> but can't figure out how to get it to do number of characters instead of a string pattern, i.e. split in the middle of the 4th and 5th digit.</p>