SDS (Shutdown Scheduler) is a utility that allows the user to automate shutting the system down or closing specified applications. It is also able to break a modem connection, restart or hibernate the system or even put it to standby mode.
Many options make the program highly customizable for your particular needs, for example, conditions under which the program will perform specified actions:
at given time,
after specified period elapses,
after the computer is idle for a specified amount of time,
when specified application is closed.
You can even combine the conditions and whichever occurs first, triggers the action. Despite the number of options, the program is really easy to use.