If your Date values are already in string then you can escape STR() function from DATEPARSE()
This is a nice workaround Mahfooj, but it seems Tableau Server doesn't honour the locale date formatting which the documentation explains it should.
The default date and time formatting in Tableau Desktop 2018.3 follows the PC locale settings.
Uploading the same workbook to Tableau server 2018.3 shows the date format in US format (MM/dd/YYYY) unless each field is manually formatted to another.
Dates in the date picker, refresh date and many more, all use this format, and it's not possible to set all of these.
The server was set to en_US locale at installation time (MM/dd/YYYY). Even changing the system locale to en_GB (dd-MM-YYYY) doesn't change the format in Tableau Server reports or any of the setting pages. The user locale is en_ZA (YYYY/MM/dd) and the server config locale is set to "Unspecified".
The documentation states the server should then either display the date in en_GB or en_ZA format.
It does neither, displaying the dates in en_US format, which no locale on the server are set to.
How do I correct this?