To calculate the duration of a script in either seconds or minutes from within the script follow these instructions.
Add a database get on the start page containing the following SQL statement;
Select Start_time from tbl_Session with (nolock) where id = [var_csSessionID]
This statement will return the start time for each script run based on the session ID.
you will need to stamp the result into either a hidden field or text box depending on if you want it to be visible.
Add a used control of the field you stamped the start time into, another field to stamp the duration into and a database get with the following SQL statement;
set dateformat dmy Select DATEDIFF (SS, [Start_Time],GETDATE()) as duration
Replace [Start_Time] with the name of your used control from the start page.
You can then stamp the result of this database get into a field to store the duration. If you want to see the duration in minutes you should replace the SS with MI.