How can I schedule a nightly reboot?

Adding this to /etc/cron.daily/zz-reboot should work:

#!/bin/sh
shutdown -r now

And sudo chmod a+x /etc/cron.daily/zz-reboot. The “zz” prefix will force it to run last out of all the other scripts in that directory. Check /etc/crontab to see what time of day that will actually happen:

grep daily /etc/crontab | awk '{print $2 ":" $1}'

If that won’t work, then a “regular” cron entry can work too, via sudo crontab -e

MINUTE HOUR * * * shutdown -r now

And finally, if you want to just do one-off reboots, you can use at:

echo "shutdown -r now" | sudo at 04:30

You should create a script using the directions given by Kees Cook…

You can just copy and paste the information below in any text editor and create the zz-reboot file in the directory suggested.

After that just remember to right click on the file and assign it execution permission.
If you feel like doing in using terminal just:

sudo chmod +x /etc/cron.daily/zz-reboot

To understand better what you’re doing remember that in /etc folder you generally find configuration files and there you can find cron.hourly, cron.daily and other cron folders.
Cron takes care of executing applications and script at a certain time.

If you want to be strict about the reboot time just digit

sudo crontab -e

so you can edit the crontab for the root user.

If you feel better doing it graphically you can install from the Software Center gnome-schedule.
If you want to modify the gnome-schedule for root user ensure that you run it from terminal:

gksudo gnome-schedule

Have fun playing around! 🙂

p.s.:
great point sBlatt! I was wondering if there’s any way to force cron.daily execution time manually.

I have been working with cronjobs for about a month at my work and scheduling poweroff, and reboot. It’s very simple. I know this was asked about 5 years ago, but if anyone still has problems, you can use this method and you will be set.

open the terminal (ctrl+T)

sudo nano /etc/crontab

scroll all the way to the bottom and enter the below command

00 6 * * * root reboot 

this is set for reboot at 6am everyday, and press enter

If you want to schedule poweroff at 11pm everyday you can enter

00 23 * * * root poweroff

I still need to figure out how to poweron a machine using cronjob when it’s down. I will edit this answer once i figure it out.

P.S. this is my first ever answer posting on any forms; hope it helps someone!! 😀

Consider

0 6 * * * sudo shutdown -r     

This will a 6 am reboot every day. I like this because it allows a 1 minute delay to shut down any other background jobs and warns anyone else that a shutdown is pending.

This is an older question, but it comes up as search result and does not contain any info about systemd, so I will add an example on how to do scheduled reboots with systemd. Filenames and unit descriptions in the example are chosen arbitrarily and can be changed.

1. Add a service unit that restarts the system. To do that, create a new file in /etc/systemd/system/sched-reboot.service and add the necessary configuration into it. The following service config will run a forced reboot through systemctl whenever started.

    [Unit]
    Description=Scheduled Reboot
   
    [Service]
    Type=oneshot
    ExecStart=/usr/bin/systemctl --force reboot
   

2. Add a timer, that will start the reboot service on a schedule. Create a new file in /etc/systemd/system/sched-reboot.timer. The following config for the timer will run the reboot service daily at 4AM

    [Unit]
    Description=Reboot Scheduling
   
    [Timer]
    OnCalendar=*-*-* 4:00:00
   
    [Install]
    WantedBy=multi-user.target
   

3. (Optional) Run systemd-analyze verify /etc/systemd/system/sched-reboot.* to check for errors in the config files. If the return is empty, the files are in order.

4. Enable and start the timer by running sudo systemctl enable sched-reboot.timer and sudo systemctl start sched-reboot.timer.

5. (Optional) Run systemctl list-timers to see all active timers as well as their next and last start information.

For more info about timers and the syntax for setting calendar events (as in OnCalendar in the example) have a look at the ArchWiki-section about Timers