title: Parse non standard date format
body: <p>Say I have the following format outputted for my date:</p>
  
  <pre><code>date --utc +%d.%m.%Y,\ %H:%M\ UTC
  # Outputs: 12.06.2014, 09:03 UTC
  </code></pre>
  
  <p>How can I display the outputted date above, in another <code>date</code> call, in another format? I tried:</p>
  
  <pre><code>date --utc --date="12.06.2014, 09:03 UTC" +%d.%m.%Y,\ %H:%M\ UTC
  </code></pre>
  
  <p>but with no success (it says <code>invalid date</code>).</p>
  
  <p>I am primarily trying to do this in order to be able to tell from an outputted date how many hours have passed (or days, or whatever time measuring unit).</p>