Please read this: https://docs.mendix.com/refguide7/date-picker?utm_source=businessmodeler&utm_medium=software&utm_campaign=modeler#2-1-date-format
The options only influence rendering the data. It does not influence the data capturing.
Both date and time will be captured by the widget and you cannot change it.
What is possible is, you could just set to show date in all view screens. And Showing date is the default option
Sadly, you can’t.
Mendix always save in datebase date and time.
Try to put your attribut in the Domain Model to Non-Localized.
And when you need to check the data behind always check with the day-from-datetime and month-from-datetime and year-from-datetime functions.
For further informations ,see
https://docs.mendix.com/refguide/datetime-handling-faq