Once you logged into your Cpanel account. You can find the cronjobs under the advanced section.
For example:
If you want to run a command or a php program on a specified time interval like once a day or once a week, you can setup cronjobs in this interface. Cron jobs allow you to run a specific command or program automatically.
How to save changes to a cronjob?
In the Command text box, add the /dev/null 2>&1 line to the end of the command. For example: Save your changes. Select the interval at which you wish to run the cronjob.
