BEGIN:VCALENDAR
VERSION:2.0
CALSCALE:GREGORIAN
PRODID:-//SabreDAV//SabreDAV//EN
X-WR-CALNAME:task-test
X-APPLE-CALENDAR-COLOR:#F1DB50
BEGIN:VTIMEZONE
TZID:Europe/Vienna
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:19700329T020000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=3
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:19701025T030000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
END:STANDARD
END:VTIMEZONE
BEGIN:VTODO
CREATED:20200702T075001Z
LAST-MODIFIED:20200702T075047Z
DTSTAMP:20200702T075047Z
UID:076201af-3079-4d4f-87e3-b9be5f2dd901
SUMMARY:initial recurring Thunderbird task
RRULE:FREQ=WEEKLY
DTSTART;TZID=Europe/Vienna:20200101T080000
DUE;TZID=Europe/Vienna:20200101T090000
END:VTODO
END:VCALENDAR