Create a Scheduled Task in Plesk 10 

1. Log into the Plesk administrative interface by navigating to https://<ip_address>:8443 as the server administrator.  A self-signed certificate may show an error in the browser in which case it is OK to accept the self-signed SSL.
2. Navigate to Domains in the left hand navigation menu and click Control Panel next to the domain..

3. This will open the control panel for that domain.  Under this new tab/window, click Websites & Domains.

4. Expand Show Advanced Operations and then click Scheduled Tasks.

5. Click Schedule New Task to create a new task. 

6. Fill out the form accordingly with the time and command to run and click OK.  The task is now created.  Click the task again and you can edit it if needed in the future.