To set the date format according to your need you need to execute the following SP on master database:
EXEC sp_configure 'default language', '23';
'23' stands for the Code of the format details of which you can get by running
select * from syslanguages
After execution of this stored proc it will ask you to Run the RECONFIGURE statement to install.
then Run
RECONFIGURE;
let me know if it works for you