code: public void addDate(ICalDate icalDate, ICalProperty property, ICalParameters parameters) {
  		if (!icalDate.hasTime()) {
  			//dates don't have timezones
  			return;
  		}
  
  		if (icalDate.getRawComponents().isUtc()) {
  			//it's a UTC date, so it was already parsed under the correct timezone
  			return;
  		}
  
  		//TODO handle UTC offsets within the date strings (not part of iCal standard)
  		String tzid = parameters.getTimezoneId();
  		if (tzid == null) {
  			addFloatingDate(property, icalDate);
  		} else {
  			addTimezonedDate(tzid, property, icalDate);
  		}
  	}
docs: Adds a parsed date to this parse context so its timezone can be applied
  to it after the iCalendar object has been parsed (if it has one).
  @param icalDate the parsed date
  @param property the property that the date value belongs to
  @param parameters the property's parameters