Report Builder - Add report Processing time

Hi,

I was wondering if there was any way to add a value field to a report, with the time it took for the report to Process.

It would probably be a text field with an Expression, but don't know how that would go.
I know that in Expression there is a value for ExecutionTime (when report began to run), but nothing about when it ends.

Can this be done? and if yes, how?

Thanks