title: ZonedDateTime toString compatability with ISO 8601
body: <p>I am trying to ensure that calling <code>toString()</code> on my <code>ZonedDateTime</code> Object will comply with ISO-8601 format.</p>
  
  <p>The documentation for the <code>toString()</code> method states:</p>
  
  <blockquote>
    <p>...The output is compatible with ISO-8601 if the offset and ID are the
    same</p>
  </blockquote>
  
  <p>Does this mean that there exists a situation where calling 
  <code>zdt.getOffset()</code>
  will return something different than 
  <code>zdt.getZone().getRules().getOffset(zdt.toInstant())</code>
  ?</p>
  
  <p>This doesn't seem to make sense.</p>
  
  <p>Can someone provide an example in which the offset and ID are not the same (ie: where <code>toString()</code> does not comply with ISO-8601) so that I can better understand the description in the documentation.</p>