Basic command to shutdown/reboot the system in terminal mode
To shutdown your system
shutdown -h now "message"This command will shutdown the system.The message can be any message you want send when shutdown/reboot.If you want to shutdown the system for a specific time,then use
shutdown -h hh:mm "message"Here hh is hours and mm is minutes.
shutdown -r now "message"To reboot the system for automated specific time then,
shutdown -r hh:mm "message"