[Linux Command] Automatic Shutdown / Reboot Ubuntu After Certain Time

This is a beginner’s guide shows how to automatically shutdown or reboot Ubuntu Linux with a given clock time or after certain time.

Linux has a shutdown command which can be run via:

shutdown [OPTIONS] [TIME] [WALL ...]

Where [OPTIONS] can be:

  • -P or --poweroff, do power off action (default option).
  • -r or --reboot, reboot the machine.
  • -h , equivalent to --poweroff.
  • -c , cancel a pending shutdown.

The [TIME] can be:

  • hh:mm, 24h clock time hour:minute.
  • +m, a certain time in minute.
  • now, same to +0.

And [WALL …] is a wall message to be sent to all logged-in users before going down.

Linux shutdown command examples:

Open terminal or log in your Ubuntu Linux server and run following command as you want.

1. Automatic shutdown or restart after certain time

All the following 4 commands will DO SAME thing: auto-shutdown system after 2 hours.

shutdown +120
shutdown -h +120
shutdown --poweroff +120
shutdown -P +120

Run either command below to restart 30 minutes later:

shutdown -r +30
shutdown --reboot +30

2. Automatic shutdown /reboot at given clock time

All the following 4 commands will DO SAME thing: automatic shutdown at 6 pm.

shutdown 18:00
shutdown -h 18:00
shutdown --poweroff 18:00
shutdown -P 18:00

Either command below will restart system at 7 am:

shutdown -r 07:00
shutdown --reboot 7:00

3. Shutdown or reboot now:

shutdown now
shutdown -r now

4. Shutdown or reboot and send message to all logged in users.

shutdown  +60 "System is going down in 60 minutes"
shutdown -r 18:00 "System will restart at 6pm"

For graphical tools to schedule shutdown / reboot your machine, scroll down and see the next post.

Merilyn Ne
Hi, I'm Merilyn Ne, a geek who has been working on Ubuntu Linux for many years and would like to write useful tips for beginners. Forgive me for language mistakes. I'm not a native speaker of English.