Creating an all day event that is usable by iCal

Support
1

I was wondering how one goes about creating an All Day event. I tried creating an event and omitting the date/time component, which looks as follows:

[event start="2023-03-20" status="public" name="My Event" end="2023-03-23" allowedGroups="trust_level_0"]

However, when I attempt to add this event to my calendar (i.e., iCal export), I get an iCal file that looks as follows:

BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Discourse//EN
BEGIN:VEVENT
UID:1679270400000_1679529600000
DTSTAMP:20230121T192236Z
DTSTART:20230320T000000Z
DTEND:20230323T000000Z
SUMMARY:My Event
END:VEVENT
END:VCALENDAR

Outlook does not recognize such an event as an all-day event. I can achieve that when I edit the iCal file myself as follows—changing the start and end timestamps to date-only values:

BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Discourse//EN
BEGIN:VEVENT
UID:1679270400000_1679529600000
DTSTAMP:20230121T192236Z
DTSTART;VALUE=DATE:20230320
DTEND;VALUE=DATE:20230323
SUMMARY:My Event
END:VEVENT
END:VCALENDAR

Is it possible to create an event that will automatically be treated by calendar software as an all-day event?