title: XMLGregorianCalendar to String conversion error
body: <p>The following code snippet works perfectly for dates with year above <code>1600</code> or so. But it gives wrong output for years like <code>1001, 1500, 1400</code> etc. Can you explain why?</p>
  
  <pre><code>SimpleDateFormat format = new SimpleDateFormat("MM/dd/yyyy");
  
  XMLGregorianCalendar cal DatatypeFactory.newInstance().newXMLGregorianCalendar("1600-01-01");
  
  String birthDate = format.format(cal.toGregorianCalendar().getTime());
  
  System.out.println(birthDate);
  </code></pre>