Turning Downtime On and Off
The first time you launch Downtime, and anytime you launch Downtime when it is turned off, you will see a window like this:
Just click Turn on Downtime. You will have to enter the Mac OS X username and password for a user that has administrative privileges on your Mac. When you enter the correct username and password, the Downtime Agent will be installed and the main Downtime window will appear. You can make settings in the Downtime window and then quit the Downtime application. Even though you have quit the Downtime application, the Downtime Agent will still be active and will enforce the rules you have set for the users of your computer.
If you want to turn off Downtime, just choose Turn off Downtime... from the Downtime menu. After you turn Downtime off, you can uninstall it by throwing the Downtime application icon in the trash. You must first turn Downtime off in order to remove the Downtime Agent before you throw away the Downtime application.