title: How to check if a date is in a given range?
body: <p>If you have a <code>$start_date</code> and <code>$end_date</code>, how can you check if a date given by the user falls within that range?</p>
  
  <p>e.g.</p>
  
  <pre><code>$start_date = '2009-06-17';
  
  $end_date = '2009-09-05';
  
  $date_from_user = '2009-08-28'; 
  </code></pre>
  
  <p>At the moment the dates are strings, would it help to convert them to timestamp integers?</p>