Once a course is over, the course admin sees the following message on the course timeline: "This course is over. Options."
Clicking on options leads you to this dialog. The course can now be Archived or Extended.
Archiving a course
If a course is archived by the course admin:
Only the course admin and co-instructors will still be able to access it
Students and TAs won't be able to access the course
All course members will be notified that the course has been archived
All course data (including responses, comments and grades) will be preserved
The course instructors can copy activities and content from the archived course and move them to courses that are currently live. You can navigate through an archived course exactly the way you navigate through a usual one.
All your archived courses are available on the Course Home page under the VIEW ARCHIVED COURSES option.
Extending a course
If you select the "Set new course end date" option, you can extend the course by as many days as necessary and continue to publish activities as usual. This can be done as many times as necessary.