@ianbutty
hey, I’m working with a slightly older version but I do see Z appear in my EM’s /templates/ical.php
$dateStart = date('Ymd\THis\Z',$EM_Event->start - (60*60*get_option('gmt_offset')));
$dateEnd = date('Ymd\THis\Z',$EM_Event->end - (60*60*get_option('gmt_offset')));
$dateModified = date('Ymd\THis\Z', $EM_Event->modified);