BEGIN:VCALENDAR
VERSION:2.0
PRODID:icalendar-ruby
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VTIMEZONE
TZID:Europe/London
BEGIN:DAYLIGHT
DTSTART:20230326T020000
TZOFFSETFROM:+0000
TZOFFSETTO:+0100
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=3
TZNAME:BST
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20231029T010000
TZOFFSETFROM:+0100
TZOFFSETTO:+0000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:GMT
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTAMP:20260412T164153Z
UID:gradball
DTSTART;TZID=Europe/London:20230523T183000
DTEND;TZID=Europe/London:20230525T010000
LOCATION:citation
SUMMARY:Gradball
END:VEVENT
END:VCALENDAR