Events don't render in Outlook ("not supported calender message.ics")

[hershkoy]

I am creating events and they look ok in gmail and even in outlook live (the web version of outlook), but on the outlook desktop version the events are received as emails with attachment:

This is the code:

date_default_timezone_set('Asia/Jerusalem');

$dtz = new \DateTimeZone('Asia/Jerusalem');
$time_in_israel = new \DateTime('now', $dtz);
$time_offest = $dtz->getOffset( $time_in_israel )/3600;

// 1. Create new calendar
$vCalendar = new \Eluceo\iCal\Component\Calendar($params['domain']);
$vCalendar->setMethod('REQUEST');
$vCalendar->setName('cal.ics');
$vCalendar->setTimezone('Asia/Jerusalem');

// 2. Create an event
$vEvent = new \Eluceo\iCal\Component\Event();
$vEvent->setSummary($params['summary']);
$vEvent->setDtStart((new \DateTime($params['dtStart']))->add(new \DateInterval("PT".$time_offest."H")));
$vEvent->setDtEnd((new \DateTime($params['dtEnd']))->add(new \DateInterval("PT".$time_offest."H"))); 
$vEvent->setNoTime(false);

$vEvent->addAttendee('MAILTO:'.$params['attendee']['mail'], $params['attendee']['data']);

$organizer = new \Eluceo\iCal\Property\Event\Organizer('MAILTO:'.$params['organizer']['mail'], $params['organizer']['data']);
$vEvent->setOrganizer($organizer);

// Adding Timezone (optional)
$vEvent->setUseTimezone(true);

// 3. Add event to calendar
$vCalendar->addComponent($vEvent);

// 4. Set headers
header('Content-Type: text/calendar; charset=utf-8');
header('Content-Disposition: attachment; filename="cal.ics"');

// 5. Output
$ical = $vCalendar->render();    

The generated ical looks like this:

BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//XXX//EN
METHOD:REQUEST
X-WR-CALNAME:cal.ics
X-WR-TIMEZONE:Asia/Jerusalem
X-PUBLISHED-TTL:P1W
BEGIN:VTIMEZONE
TZID:Asia/Jerusalem
X-LIC-LOCATION:Asia/Jerusalem
END:VTIMEZONE
BEGIN:VEVENT
UID:60a6438f1789a
DTSTART:20210607T010000Z
SEQUENCE:0
TRANSP:OPAQUE
DTEND:20210607T011500Z
SUMMARY:test ical english12
ATTENDEE;ROLE=REQ-PARTICIPANT;PARTSTAT=NEEDS-ACTION;RSVP=TRUE;CN=my_admin_n
 ame:MAILTO:[email protected]
CLASS:PUBLIC
ORGANIZER;CN=name:MAILTO:[email protected]
DTSTAMP:20210520T111007Z
END:VEVENT
END:VCALENDAR

I understand that I need to make it pass a validator. At the moment there is a fail:

At least one STANDARD or DAYLIGHT property must be defined here near line # 8
Reference: RFC 5545 3.6.5. Time Zone Component

What do I need to change in the code?

I am using ical version 0.11.6

[markuspoerschke]

If you want to ensure consistent TimeZone-Support, the transitions of daylight saving and standard time need to be defined manually. You can have a look at examples/example5.php how this can be done.