You can specify, through the dtpower window, the timing conditions that will cause your system to shut down automatically. This feature is called AutoShutdown.
Be sure to read "Choosing to Use Power Management" before changing the AutoShutdown settings.
AutoShutdown uses the Suspend feature to automatically power off your system. When the system powers up again, it resumes in the state in which it was suspended.
Through the dtpower window, you can activate or deactivate the AutoShutdown and AutoWakeup features. You can also specify the following time values:
The number of minutes of idle time before AutoShutdown attempts to suspend the system
The start and finish times when AutoShutdown can occur during each day (if you specify the same time for both start and finish, AutoShutdown can occur at any time of day)
The time of day when the system will automatically power on and resume (AutoWakeup) after being suspended by AutoShutdown (available on sun4u desktop systems only)
AutoWakeup does not occur after you Suspend a system manually; it can occur only after an AutoShutdown.