title: can not open ics file on iPhone
body: <p>I'm doing testing .ics file samples on my iPhone.<p>
  But when I open .ics file, same message keeps showing as belows:<p>
  <code>"This invitation data has been expired."</code>  (I'm not sure if this translation is correct...) <p>
  I can't even open other sample files. Just same messages are showed up.
  <br/><br/></p>
  
  <p>Here is the code of sample file.<p></p>
  
  <pre><code>BEGIN:VCALENDAR
  VERSION:2.0
  PRODID:-//hacksw/handcal//NONSGML v1.0//EN
  BEGIN:VEVENT
  UID:uid1@example.com
  DTSTAMP:20160714T170000Z
  ORGANIZER;CN=John Doe:MAILTO:john.doe@example.com
  DTSTART:20160714T170000Z
  DTEND:20160715T035959Z
  SUMMARY:Bastille Day Party
  END:VEVENT
  END:VCALENDAR
  </code></pre>
  
  <p><br/><br/>
  Any suggestions? <p>
  I hope you understand my Enligsh. Thanks.</p>