A command to an operating system or server for a job that is to be executed at a specified time:a cron job...
All we need to do is run the client script on the testing servers as a cron job.
On-line updating can now be set up as a cron job to reach out to the server of your choice at the time of your choosing, check for available updates and download and install them without user interaction.
A cron job automation example to handle this is explained later in this article.