Hello Roel,
Unfortunately this is an issue on the SQL side of things. Dynamic Forms has no idea how to show a date in a certain format if the page is being viewed in a particular language.
You may want to consider working on your query in the Initial SQL Bind section of your Dynamic Form. Here's what I would do if the date needs to be a different format based on the LanageCode on the page:
Select (case when '$(LanguageCode)' = 'NL-nl' THEN Convert(char(10), getDate(),103) ELSE Convert(char(10), getDate(),101) END) As DateShortFieldName
SO the focal point is that you can conditionally change the Date format based on the LanguageCode.
PLEASE NOTE:
The DATE Question type in Dynamic Forms only works with US Date Format. You may need to use a Textbox instead and configure a Datepicker. You can learn more on configuring Date fields for Dynamic Forms on Demonstration 28:
http://www.datasprings.com/formdemos Please let me know if this assists you, or if you have any questions.
Thanks,
Ryan