Nope. The format used to submit results to the server of type date is prescribed and fixed by the XForms specification. However you can convert to/from pretty much any custom format you desire using the format-date() function.
For example, to get something like “09/10/19” you can use:
format-date(${mydate}, '%d/%m/%y')
If you use this in a calculation, your calculation result will contain your date in your desired format when submitted to your server.
