How to make a date repeat every year for the last day of February in java for iCal google-rfc-2445

I need to repeat a date every last day of February, I am using Joda time to use a rule to generate the dates for days, weeks, months, etc. For Months is working fine but when is about years I receive wrong outputs.

private static List<DateTime> calculateRecurrentDates(DateTime startDate, String recurrentRule) {
    List<DateTime> dates = new ArrayList<DateTime>();
    TimeStamp startDate = Timestamp.valueOf("2011-02-28 10:10:10");
    String recurrentRule = "RRULE:FREQ=YEARLY;COUNT=6;INTERVAL=1;";
    String leapYearRule = "RRULE:FREQ=YEARLY;COUNT=6;INTERVAL=1;BYMONTHDAY=28,29;BYSETPOS=-1";

    try {
        DateTimeIterable range = DateTimeIteratorFactory.createDateTimeIterable(recurrentRule, startDate, DateTimeZone.UTC, true);
        for (DateTime date : range) {
           dates.add(date);
        }
    } catch (ParseException e) {
        dates = null;
        logger.error(e.getMessage());
    }
    return dates;
}

But I receive this:

2011-02-28T10:10:10.000Z
2012-02-28T10:10:10.000Z
2013-02-28T10:10:10.000Z
2014-02-28T10:10:10.000Z
2015-02-28T10:10:10.000Z
2016-02-28T10:10:10.000Z

and in the case is in a leap year this:

2012-02-29T10:10:10.000Z
2012-12-29T10:10:10.000Z
2013-12-29T10:10:10.000Z
2014-12-29T10:10:10.000Z
2015-12-29T10:10:10.000Z
2016-12-29T10:10:10.000Z
2017-12-29T10:10:10.000Z

How I write one rule to get the last day of February every year?

My solution is to count from the last day of the year to the day before March 1st. So the rule will be like this:

"RRULE:FREQ=YEARLY;COUNT=6;INTERVAL=1;BYYEARDAY=-307"