public IntervalListDayOfWeek(ColumnGroup columnGroup) {
super(columnGroup);
intervalMap = new HashMap<Integer, Interval>();
DayOfWeek firstDay = columnGroup.getFirstDayOfWeek();
int index = firstDay.getIndex();
DayOfWeek[] array = DayOfWeek.getAll();
for (int i = 0; i < array.length; i++) {
DayOfWeek dayOfWeek = array[index];
Interval interval = new Interval(dayOfWeek.toString());
this.add(interval);
intervalMap.put(index, interval);
index = DayOfWeek.nextIndex(index);
}