[[!meta title="MIT SIPB Scheduled Jobs Service (Cron)"]]
The scheduled jobs service uses
[cron](http://www.google.com/search?q=cron) to allow people to set
up scripts to run at certain times. Although this service has been
designed with reliability in mind, it should not be used to run
critical applications that cannot tolerate downtime.

#### **To sign up for the service:**

athena% add scripts  
athena% signup-cron

(If you are confused about how to run the above commands on Athena,
e-mail scripts@mit.edu for assistance. You must have an
[Athena account](http://web.mit.edu/olh/Register/) and understand
the
[MITnet rules of use](http://web.mit.edu/olh/Welcome/rules.html) in
order to use the service.)

This signup process will create a **cron\_scripts** directory and
place a sample crontab file in it. This provided crontab contains
some information that should help you get started. Changes to your
crontab will never take effect until you explicitly load your
crontab. You can do so by changing to the `cron_scripts` directory
and running `cronload crontab` (if you do so from Athena, make sure
you have previously run `add scripts` in your login shell).

Finally, add yourself to the
[scripts-announce mailing list](https://mailman.mit.edu/mailman/listinfo/scripts-announce)
if you would like to receive announcements of major service changes
and outages. This list receives less than one e-mail per month on
average.

For more information, see our list of
[Frequently Asked Questions](../faq/).