code: public List<DateTimePeriod> toDays() {
          ArrayList<DateTimePeriod> list = new ArrayList<DateTimePeriod>();
  
          // default "current" day to start datetime
          DateTime currentStart = getStart();
          // calculate "next" day
          DateTime nextStart = currentStart.plusDays(1);
          // continue adding until we've reached the end
          while (nextStart.isBefore(getEnd()) || nextStart.isEqual(getEnd())) {
              // its okay to add the current
              list.add(new DateTimeDay(currentStart, nextStart));
              // increment both
              currentStart = nextStart;
              nextStart = currentStart.plusDays(1);
          }
          
          return list;
      }
docs: Converts this period to a list of day periods.  Partial days will not be
  included.  For example, a period of "January 2009" will return a list
  of 31 days - one for each day in January.  On the other hand, a period
  of "January 20, 2009 13:00-59" would return an empty list since partial
  days are not included.
  @return A list of day periods contained within this period