Invoke-SQLCmd Date output format
If you are on SQL-Server 2012 or above you can use FORMAT function in your stored procedure.
FORMAT ( value, format [, culture ] )

DECLARE @d DATETIME = GETDATE();   
SELECT FORMAT( @d, 'dd/MM/yyyy', 'en-US' ) AS 'DateTime Result'  

If you use an older version you can use CONVERT:
CONVERT ( data_type [ ( length ) ] , expression [ , style ] )

SELECT CONVERT(varchar(10), @d, 103);



| DateTime Result |
| :-------------- |
| 31/05/2011      |

| (No column name) |
| :--------------- |
| 31/05/2011       |


db&lt;&gt;fiddle here