I am attempting to reproduce this style with the

You can change the logic to include all the dates between the two selected dates.

For example, you can add this code in between the two if statements :

if (selectedStartItem != null && selectedEndItem != null) {
  Long l = selectedStartItem   86401000;
  for (; l < selectedEndItem;) {
    selections.add(l);
    l = l   86401000;
  }
}

The function will look like this :

The coloring part is executed in the