Select Auto-Save from the File menu to display this window.

When there is no √ mark next to Auto-Save in the File menu and you select Auto-Save in the File menu, you will be asked to confirm that you want to turn on Auto-Save for this document.  Click on OK to activate Auto-Save.  The time duration is set in the Preferences.  Selecting Auto-Save again turns off Auto-Save and removes the √ mark.

In this example, the file “myTime” is saved to disk every 5 minutes.  This is helpful in the event your Mac ever crashes (not your Mac!).

See the chapter on Preferences for more information.