If you charge out your computer time, use it to work out how much time you have spent on a each program.

The log of all running programs is always available.

Log all windows to show all running software.

To start record of user activity - select "Enabled Log user activity" in the "Tools" menu.

To see log of all running software - select "View Log" in the "Tools" menu.

If necessary you may save the current logs on disk and analyse it later.