I have this application, and the default date format must be dd/MM/yyyy (the language is Brazilian Portuguese).
dd/MM/yyyy
I already had set culture and UI culture
I found what happended. My form was posting via GET method, and the MVC just uses the culture for an action parameter when it's passed in the RouteData or by the form via POST method.
GET
RouteData
POST
I just changed the form to POST method and it worked.