Custom form with QT for QGIS 3.4, Date edit Widget, Null value

Question

I made a custom form for QGis with QT-designer and I have a problem with the Date-Widget.

When I create a form in QGIS with drag and drop or automatically, then it works: Fore a date-field I can choose Date/Time and there I can choose the Null-Value as standard. And the calendar pop-up shows the actual date.

Is there a possibility to this with QT-Designer? I don't find a possibility there to choose the Null-Value as standard (I don't find at all to choose the Null-Value). And for the Date I have to choose a concrete date and cannot use the actual date (now()).

Answer 1

Till now I used the QT Designer without the custom widgets for QGIS. With the help of this post: No custom widgets in Qt Designer for QGIS 3 I got the custom widgets for QGIS3 in QT Designer and there is the widget QgsDateTimeEdit which makes what I want!