BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//icalendar//test//EN
BEGIN:VEVENT
UID:invalid-duration@example.com
DTSTAMP:20240101T000000Z
DTSTART:20240101T000000Z
DURATION:P999999999999999999W
SUMMARY:Event with an impractical duration
END:VEVENT
END:VCALENDAR