title: SAS Date and substracting 1 Month
body: <p>I have a date that is stored as a number that is 201401. I would like to subtract 1 month, so that is 201312 and not 201400. </p>
  
  <p>Also, if there is a more efficient way, please suggest as well. I also have the date stored as 01Jan2014, and would be fine converting the SAS date at that point, so that I can create two new columns (with 1 month subtracted) so that they have the value 01Dec2013 and 201312. Also, a function for incrementing the month forward or backward would be much appreciated. </p>
  
  <p>Thanks in advance.</p>