When you start the edition of a DatePicker, and then you move with the arrows of your keyBoard, it's your focus that is changing. Then pressing enter will change the value, triggering any changeListener listening to the selectionModel.

But in a ComboBox. If you open it and move with the arrows, you are directly changing the selection.

So I don't quite understand why we don't have a coherent behavior between those two controls, especially when you know that a datePicker is extending ComboBoxBase.