It seems I can shutdown using
sudo shutdown by specifying a time or minutes.
Is there a way to specify datetime for shutdown?
You can do this directly from the
shutdown command, see
SYNOPSIS /sbin/shutdown [-akrhPHfFnc] [-t sec] time [warning message] [...] time When to shutdown.
So, for example:
shutdown -h 21:45
That will run
shutdown -h at 21:45.
For commands that don't offer this functionality, you can try one of:
at daemon is designed for precisely this. Depending on your OS, you may need to install it. On Debian based systems, this can be done with:
sudo apt-get install at
There are three ways of giving a command to
$ echo "ls > a.txt" | at now + 1 min warning: commands will be executed using /bin/sh job 3 at Thu Apr 4 20:16:00 2013
Save the command you want to run in a text file, and then pass that file to
$ echo "ls > a.txt" > cmd.txt $ at now + 1 min < cmd.txt warning: commands will be executed using /bin/sh job 3 at Thu Apr 4 20:16:00 2013
You can also pass
at commands from STDIN:
$ at now + 1 min warning: commands will be executed using /bin/sh at> ls
Then, press CtrlD to exit the
at shell. The
ls command will be run in one minute.
You can give very precise times in the format of
[[CC]YY]MMDDhhmm[.ss], as in
$ at -t 201403142134.12 < script.sh
This will run the script
script.sh at 21:34 and 12 seconds on the 14th of March 2014.
The other approach is using the
cron scheduler which is designed to perform tasks at specific times. It is usually used for tasks that will be repeated but you can also give a specific time. Each user has their own "crontabs" which control what jobs are executed and when. The general format of a crontab is:
* * * * * command to be executed - - - - - | | | | | | | | | +----- day of week (0 - 6) (Sunday=0) | | | +------- month (1 - 12) | | +--------- day of month (1 - 31) | +----------- hour (0 - 23) +------------- min (0 - 59)
So, for example, this will run
ls every day at 14:04:
04 14 * * * ls
To set up a cronjob for a specific date:
Create a new crontab by running
crontab -e. This will bring up a window of your favorite text editor.
Add this line to the file that just opened. This particular example will run at 14:34 on the 15th of March 2014 if that day is a Friday (so, OK, it might run more than once):
34 14 15 5 /path/to/command
Save the file and exit the editor.
This SO answer suggests a way to have it run only once but I have never used it so I can't vouch for it.
No you can't specify a date at the shutdown command but two alternatives exist:
1) The easiest is to use the at command. The following example will execute
shutdown +5 at a specific time and day:
echo "shutdown +5" | at 10:05am 2019-01-19
2) if you don't mind using you calculator and want to shutdown in say 24hours (24*60=1440 minutes) and you're absolutely sure the system will not reboot in between:
shutdown -r +1440
It will shutdown your system at 12:00 :
$ sudo shutdown -h 12:00
-h, -P, --poweroff
Power-off the machine.
Reboot the machine.
Cancel a pending shutdown.