If you use QuarkXpress beyond the grace period without activating, it will operate in reduced-functionality mode, which prevents you from saving and printing documents (along with other limitations).
For more details about reduced functionality, go through the link - Reduced functionality
QuarkXPress® 9 evaluation expires after 30 days whereas evaluation version of QuarkXPress® 8 expires after 60 days.
If you decide to buy QuarkXPress 9, you don’t have to reinstall anything.You can move directly from your fully functional 30-day QuarkXPress 9 Test Drive to a regular commercial version by entering your validation code issued at purchase, quitting the application, and then simply relaunching QuarkXPress 9.