Hello there, @patyl ...
I understand that you want to know how to set up an assignment so that it qualifies less if the assignment is submitted late. You will want to take a look at this Guide:
How do I apply a Late Submission policy in the Gra... - Instructure Community (canvaslms.com)
Hopefully the information here will be helpful to you so that you can set up your assignment to deduct a certain amount based on a late submission.
Please let Community members know if you have any other questions about this. Thank you!
... View more