When you use PowerApps form overlaying a
SharePoint List, you may have noticed that Date Fields often default strangely, e.g., in this example when creating a new list item, it defaults to US format (MM/DD/YYYY), and to the 31st December 2001. Not very useful!
To make sure this does not happen, there are two simple steps:
1. Change the date format to UK by specifying the "Format" property of the Date Picker Control as "dd/mm/yyyy" as shown below,
and 2. Blank the "InputTextPlaceholder" property of the Date Picker control as shown below