Clear the calendar

I've set dialogCaldroidFragment.setBackgroundDrawableForDates(bgForDate);
            dialogCaldroidFragment.setTextColorForDates(textColorForDate);
How do i clear the previous values and set new??

also tried dialogCaldroidFragment.getBackgroundForDateTimeMap().clear();
        dialogCaldroidFragment.clearSelectedDates();
        dialogCaldroidFragment.refreshView();
but got nothing