sample ics: BEGIN:VEVENT
DTSTART;TZID=W. Europe:20231123T100000
DTEND;TZID=W. Europe:20231123T123000
TRANSP:OPAQUE
RDATE;TZID=W. Europe;VALUE=PERIOD:20231123T100000/20231123T123000
RECURRENCE-ID:20231116T090000Z
DTSTAMP:20231113T114638Z
SEQUENCE:2
ATTENDEE;PARTSTAT=ACCEPTED;CN=Test Attendee;RSVP=FALSE:[email protected]
CLASS:PUBLIC
SUMMARY: Test Event
LOCATION:test
ORGANIZER;CN=test/ASSBZ:mailto:[email protected]
UID:F2CCF1D60607A08BC12588D3002960B6
END:VEVENT

` if (component.hasProperty('rdate')) {
this.ruleDates = this._extractDates(component, 'rdate');

    // special hack for cases where first rdate is prior
    // to the start date. We only check for the first rdate.
    // This is mostly for google's crazy recurring date logic
    // (contacts birthdays).
    if ((this.ruleDates[0]) &&
        (this.ruleDates[0].compare(this.dtstart) < 0)) {

      this.ruleDateInc = 0;
      this.last = this.ruleDates[0].clone();
    } else {
      this.ruleDateInc = ICAL.helpers.binsearchInsert(
        this.ruleDates,
        this.last,
        compareTime
      );
    }

    this.ruleDate = this.ruleDates[this.ruleDateInc];
  }`

This code snippet is from _init() method which is failing and its failing while comparing ruleDates with dtstart because ruleDates[0] is an object and compare is not defined on that
ruleDates[0]: {end: icalTime, start: icalTime} which is an instance of icalperiod