title: Convert UK date to US date in PHP with different separator
body: <p>How would you convert UK date to US date in PHP without much regard to separator:</p>
  
  <p>e.g.</p>
  
  <pre><code>01/01/2012
  
  to 
  
  2012-01-01
  </code></pre>
  
  <p>Thanks in advance!</p>