title: How to parse a string of format "YYYYMMDD" to a Timex.Parse.DateTime type?
body: <p>I want to use Paul Schoenfelder's awesome <a href="https://github.com/bitwalker/timex" rel="nofollow">Timex</a> library to parse a simple string of format "YYYYMMDD" into a <code>Timex.Parse.DateTime.t</code> type.</p>
  
  <p>Right now, I'm doing something like this:</p>
  
  <pre><code>{:ok, dt} = Timex.parse "20161111", "{YYYYDDMM}"
  ** (MatchError) no match of right hand side value: {:error, {:format, "Expected at least one parser to succeed at line 1, column 0."}}
  </code></pre>
  
  <p>This code above, doesn't work. But when I do this:</p>
  
  <pre><code>{:ok, dt} = Timex.parse "2016", "{YYYY}"        
  {:ok, #&lt;DateTime(2016-01-01T00:00:00Z)&gt;}
  </code></pre>
  
  <p>I get <code>dt</code> assigned as a <code>DateTime</code> variable.</p>
  
  <p>What am I doing wrong?</p>
  
  <p>Thanks in advance :D</p>