title: Convert timestamp to integer
body: <p>How can I convert the following timestamp into the an integer form, ideally milliseconds after 1970.... </p>
  
  <pre><code>       s = '2014-02-11-00_40_05'
  </code></pre>
  
  <p>I have tried using:</p>
  
  <pre><code>       out = datevec(s)
  </code></pre>
  
  <p>However I receive an error saying 'Too many date fields in
  2014-02-11-00_40_0'</p>
  
  <p>Thanks</p>