QDateEdit/CalendarPopup(true) has incorrect sizing

When setting CalendarPopup to true for a QDateEdit the minimumSizeHint does not increase in width.

This is a problem because the widget's button size increases (see screenshots) causing the date to not get enough space.

The problem is caused by QDateTimeEdit inheriting and using QAbstractSpinBox.
This a design flaw as it is a combobox, not a spinbox when CalendarPopup is true.

To fix this:
1) A QAbstractComboBox must be developed
2) QDateTimeEdit must inherit QWidget, not QAbstractSpinBox
3) QAbstractSpinBox or QAbstractComboBox must be applied based on the value of CalendarPopup

The current QDateTimeEdit class is BROKEN and is based on a FLAWED DESIGN.