incorrect date shown for recurring VEVENT starting in 1604

[christf]

I maintain and synchronize my calendars using radicale. The birthday calendar is automatically generated using a python script. One of the entries looks like this:

BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//PYVOBJECT//NONSGML Version 1//EN
BEGIN:VEVENT
UID:xxxxxxxxx-xxxx-xxxxx-xxxx-xxxxxxxxxxxxxx
DTSTART;VALUE=DATE:16041215
DTEND;VALUE=DATE:16041216
DTSTAMP:20250319T233827Z
RRULE:FREQ=YEARLY
SUMMARY:Donald Duck
END:VEVENT
END:VCALENDAR

The problem is, that this years birthday for poor Donald is being displayed in Etar on april 5th.