There are two ways to do that (on Windows):

 

1) Using the Wizard ("powertools" menu).
If you create a new job the last screen of the wizard lets you schedule the job. I you choose that option, the Windows built-in scheduler will be opened automatically. If you have a jobfile already you can open it from the wizard, step through the wizard and choose "schedule" on the last screen.

 

2) Using the User Interface of the Scheduler itself.
This of course can be done as well. The Windows' built-in scheduler is in the Control Panel ... Scheduled Tasks. If you want to use another scheduler than the built-in you must use this second method. And if you want to schedule a .bat file (or any other executable file) calling SJA this method must be used too.