public static WeekDayNumData[] parseWeekDay(String[] weekDays) {
        WeekDayNumData[] retVal = null;

        if(weekDays != null){
            retVal = new WeekDayNumData[weekDays.length];
            int i = 0;
            for(String s : weekDays){
                WeekDayNumData element = new WeekDayNumData();
                if(s.length() == 4){
                    element.setOccurence(Integer.parseInt(s.substring(0,2)));
                    element.setWeekday(RecurrenceRuleData.WEEKDAY.valueOf(s.substring(2)));
                } else if(s.length() == 3){
                    element.setOccurence(Integer.parseInt(s.substring(0, 1)));
                    element.setWeekday(RecurrenceRuleData.WEEKDAY.valueOf(s.substring(1)));
                } else if(s.length() == 2){
                    element.setWeekday(RecurrenceRuleData.WEEKDAY.valueOf(s));
                }
                retVal[i++] = element;
            }
        }
        return retVal;
    }