title: Convert number to date in php
body: <p>I need to convert a variable</p>
  
  <pre><code>$date = 20130521201511
  </code></pre>
  
  <p>to</p>
  
  <pre><code>$date = 2013-05-21 20:15:11
  </code></pre>
  
  <p>however I am not quite sure how to do so.</p>