BEGIN:VCALENDAR
VERSION:2.0
PRODID:icalendar-ruby
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VTIMEZONE
TZID:Europe/London
BEGIN:DAYLIGHT
DTSTART:20200329T020000
TZOFFSETFROM:+0000
TZOFFSETTO:+0100
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=3
TZNAME:BST
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20191027T010000
TZOFFSETFROM:+0100
TZOFFSETTO:+0000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:GMT
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTAMP:20260625T082335Z
UID:12-3-watch-captain-marvel-free-at-the-su
DTSTART;TZID=Europe/London:20200312T193000
DTEND;TZID=Europe/London:20200312T220000
LOCATION:1st floor (SU Building) 
SUMMARY:12/3 - Watch Captain Marvel free at the SU
END:VEVENT
END:VCALENDAR