When you start typing or alter a report in some way, the auto save countdown will start.

 

The actual countdown is displayed at the bottom of the editor section of the screen.

 

You can alter the frequency of the auto save or change the function so it is just an alarm that will remind you to save:

 

From within the options window, click the 'Functionality' icon.

 

You should be able to select different auto save frequencies or turn off the feature altogether.  By changing the 'Auto save' option from a 'Yes' to a 'No' you will make the function into an alarm to remind you to save.