BEGIN:VCALENDAR
VERSION:2.0
PRODID:icalendar-ruby
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VTIMEZONE
TZID:Europe/London
BEGIN:DAYLIGHT
DTSTART:20260329T020000
TZOFFSETFROM:+0000
TZOFFSETTO:+0100
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=3
TZNAME:BST
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20261025T010000
TZOFFSETFROM:+0100
TZOFFSETTO:+0000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:GMT
END:STANDARD
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BEGIN:VEVENT
DTSTAMP:20260919T073434Z
UID:christian-union-catch-up
DTSTART;TZID=Europe/London:20260921T121500
DTEND;TZID=Europe/London:20260921T130000
LOCATION:yourSU @cityspace
SUMMARY:Christian Union catch up 
END:VEVENT
END:VCALENDAR