BEGIN:VCALENDAR
VERSION:2.0
PRODID:spatie/icalendar-generator
BEGIN:VTIMEZONE
TZID:Europe/Vienna
BEGIN:STANDARD
DTSTART:20221030T030000
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
END:STANDARD
BEGIN:DAYLIGHT
DTSTART:20230326T030000
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
END:DAYLIGHT
END:VTIMEZONE
BEGIN:VTIMEZONE
TZID:UTC
BEGIN:STANDARD
DTSTART:20220314T035119
TZOFFSETFROM:+0000
TZOFFSETTO:+0000
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
UID:mzs.at@salz21-144
DTSTAMP:20221209T035119Z
SUMMARY:salz21 
LOCATION:Am Messezentrum 1\, 5020
DTSTART;TZID=Europe/Vienna:20230315T000000
DTEND;TZID=Europe/Vienna:20230317T000000
END:VEVENT
END:VCALENDAR