I believe the following widget has this option:
https://marketplace.mendix.com/link/component/115226
Might be worth checking out. I don't believe the standard datepicker has this functionality.
You can do this multiple ways, an easy solution is with a on change event which checks if the entered date is > CurrentDateTime.
you can select “Date in the past” in the properties of the date picker widget
How disabled past date in dateFilter, I have 2 dateFilter(start date and end date) and disabled past dates in the end date according to the start date