Describe the bug
I'm trying to create an RDate rule with LocalDate (s), e.g.

RDATE;VALUE=DATE:20241226,20241228

The sample event should have following rules:
RRULE:FREQ=DAILY;INTERVAL=2;UNTIL=20241231;WKST=MO
EXDATE;VALUE=DATE:20241225,20241227
RDATE;VALUE=DATE:20241226,20241228

When I use the calculateRecurrenceSet I get an Exception:
Exception in thread "main" java.time.DateTimeException: Unable to obtain Instant from TemporalAccessor: 2024-12-28 of type java.time.LocalDate

This gets thrown by the
Instant.class
and the method
public static Instant from(TemporalAccessor temporal) {

This method is called by the
Period.class:
and the method
private PeriodList subtractInterval(Period period)

in the line:
var thatInterval = TemporalAdapter.isFloating(getStart())
? period.toInterval(TimeZones.getDefault().toZoneId()) : period.toInterval();

My understanding is that period.toInterval() is not working if period is a LocalDate.
I think this should be something like:
Instant instant = period.atStartOfDay().toInstant(TimeZones.getDefault().toZoneId());

Or am I missing something?

If you set the RDATE to 20241226T000000Z,20241228T000000Z

it works fine ... but then why are DATE values supported?

BTW: There is no issue with EXDATE

Here's my sample code:
VEvent vEvent = new VEvent(LocalDate.of(2024, 12, 21), "Test");
RRule rrule = new RRule("FREQ=DAILY;INTERVAL=2;UNTIL=20241231;WKST=MO");

	ExDate<LocalDate> exdate = new ExDate<LocalDate>("20241225,20241227");
	exdate.add(new Value("DATE"));

	RDate<LocalDate> rdate = new RDate<>();
	rdate.add(new Value("DATE"));
	rdate.setValue("20241226,20241228");
	
	vEvent.add(rrule);
	vEvent.add(rdate);
	vEvent.add(exdate);
	
	Period<LocalDate> period = new Period<LocalDate>(LocalDate.of(2024, 12, 10), LocalDate.of(2025, 1, 10));
	Set<Period<LocalDate>> calculateRecurrenceSet = vEvent.calculateRecurrenceSet(period);
	
	for (Period<LocalDate> p : calculateRecurrenceSet) {
		System.out.println(p.getStart() + " " + p.getEnd());
	}

Expected behavior
The result I would expect is:
2024-12-21 2024-12-21
2024-12-23 2024-12-23
2024-12-26T00:00Z 2024-12-26T00:00Z
2024-12-28T00:00Z 2024-12-28T00:00Z
2024-12-29 2024-12-29
2024-12-31 2024-12-31

Environment (please complete the following information):

• OS: WIndows 10
• Java Version 23
• iCal4j Version 4.0.7

All the best for 2025 and thank you very much for the great library.

Thank you very much in advance for your feedback

Alex