qml date property onValueChanged signal not called when first set to 1/1/1970

Hi,
In a qml object I set a property of type date, not initialized, called selectedDate (for instance)
I change its value to 1/1/1970 from a string using Date.fromLocaleDateString
the signal "onSelectedDateChanged" is not called.
If I set it to any other valid value the signal is called
If I then set it to 1/1/1970 (or 01/01/1970), the signl is called.

Attached a Qt creator project to reproduce it.
you can enter the date in a TextEdit and validate it by clicking a button.
The onEditingFinished signal of the TextEdit tests the validity of the date inserted and set it to the date property selectedDate and displays a text to say so
onSelectedDateChanged signal should then be called and display a text.
When the first valid date I enter is 1/1/1970, the onEditingFinished text is displayed but not the onSelectedDateChanged text.
When entering any other valid date, both texts are displayed
When entering 1/1/1970 again, both texts are displayed