BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Synthetic fixtures//EN
X-CUSTOM-CALENDAR:keep this
BEGIN:VTIMEZONE
TZID:Synthetic/Fixed
BEGIN:STANDARD
DTSTART:19700101T000000
TZOFFSETFROM:+0200
TZOFFSETTO:+0200
TZNAME:FIXED
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
UID:synthetic-series
DTSTAMP:20250101T000000Z
DTSTART;TZID=Synthetic/Fixed:20250301T100000
DTEND;TZID=Synthetic/Fixed:20250301T110000
RRULE:FREQ=WEEKLY;COUNT=10
EXDATE;TZID=Synthetic/Fixed:20250308T100000
RDATE;TZID=Synthetic/Fixed:20250310T100000
SUMMARY:Recurring synthetic event
DESCRIPTION:Original
X-CUSTOM-EVENT;X-PARAM=kept:keep this too
BEGIN:VALARM
ACTION:DISPLAY
TRIGGER:-PT15M
DESCRIPTION:Reminder
END:VALARM
END:VEVENT
BEGIN:VEVENT
UID:synthetic-series
DTSTAMP:20250101T000000Z
RECURRENCE-ID;TZID=Synthetic/Fixed:20250315T100000
DTSTART;TZID=Synthetic/Fixed:20250315T120000
DTEND;TZID=Synthetic/Fixed:20250315T130000
SUMMARY:Detached override
X-OVERRIDE:keep detached
END:VEVENT
END:VCALENDAR