Right now, a teacher can view all of the terms for the year on pages with reports, however, they cannot run reports for terms once the default days have passed. My suggestion is to hide terms on pages with reports (Class Rosters, for example) if the teacher can no longer run reports for that term. This will decrease confusion for teachers who are attempting to run reports, as they will clearly see that they can only run the reports for the periods that appear in the drop down menu.