As a faculty member, you can adjust the official dates of your course. You may wish to do this to allow students to access course materials early, or to allow a period of time at the end of the course for accepting work or grading.
If you would like to change the start or end date or your course, click on the Settings tab within your course, and then click "General Info".
Scroll down to the "When is this available?" area and adjust the start or end date there.