title: how to convert date string to time interval in PHP
body: <p>how can I convert a preset date string to a time interval? The date string is in the format of <code>d/m/Y g:i:s A</code>?</p>
  
  <p>I tried the following, but it returns nothing:</p>
  
  <pre><code>$date = ... time format set above ....;
  echo strtotime($date); //returns nothing.
  </code></pre>
  
  <p>Sample date - 24/08/2011 11:47:09 PM</p>