Ideally this would be tested on Oracle & MSSQL Create and Assignment Set the due date to 1 weeks time, set the cut off date to 1 weeks time (both default) Login as a student, verify you can submit to the assignment Login as a teacher and edit the settings, change the due date to yesterday Login as a student, the assignment should say "Time remaining | Assignment is overdue by: 1 day", and still let you submit Login as a teacher and edit the settings, change the cut off date to yesterday Login as a student, the assignment should say "Time remaining | Assignment is overdue by: 1 day" and you should not be able to submit Login as a teacher and grant the student an extension until tomorrow (assignment grading interface - choose grant extension from the menu against each submission) Login as a student, the assignment should say "Extension due date | (date), Time remaining | (some number of hours) ", and still let you submit Login as a teacher and try and grant an extension before the duedate/cutoffdate. Form should fail validation and not let you save the extension.