Dash uses the date format specified by your browser. This is shown in date fields in assets.
If you are seeing the wrong format, make sure your browser is set to the correct region.
Ensure that the preferred language is at the top of the list:
Change your regional settings in System Preferences and make sure your desired language is at the top of the list.
Open Edge settings, choose "Languages" in the sidebar then ensure your preferred language is as the top.