-14 Days Ago

I am trying to see whether a data in an array pulled from a MySQL DB (YEARMONTHDATE) is older than 14 days ago. I am trying to do this in PHP. My code looks like: if($array['due'] <= $today - 14) { echo "<h5>Assignment In Void:</h5><br><h4>Assignments in the void are read-only"; require('footer.php'); exit; }. I am having problems with the math. How do I do a date subtraction without ending up with something like 20040994 (not a valid date)? Thanks, Cole