Normally you would handle this in the UI not within the database.
Since you didn’t tell us the database platform, I’ll assume Microsoft SQL Server as you are using ASP.
If you were going to do it within the database…
If the datatype of the column is DATETIME then you can either use the CONVERT function to convert the value into the correct format. You would want to convert into with 103.
SELECT CONVERT(VARCHAR(10), YourColumn, 103) as YourColumn
You can set the DATEFORMAT option to dmy within your stored procedure.
CREATE PROCEDURE YourProcedure ...
SET DATEFORMAT dmy
You can change the language of the login which your web application is using to log into the database to British English which will switch the date formatting to the British format.
The SET DATEFORMAT option is usually the preferred option if you want to make the change within the database.
IF you were going to do it within the ASP code use the DATEFORMAT function.