Setting dates on discussion topics is a special case because they are two different options: Visibility vs. Locking. This tutorial will try to explain how each behaves. NOTE - You should never set both visibility and locking options! Choose one or the other. Setting both of these dates can cause confusion for the students based on each option behave.It would be a good idea to watch the video tutorial which will provide a visual way of understanding this subject. You might also want to view the tutorial on how to set these dates: Add Start, End, Availability, and Locking Dates to a Discussion. NOTE - You should never set these dates in the discussion forum. Dates should only be set on the individual discussion topics. If you are not sure the difference between a discussion forum or topic, please review the tutorial on Understanding the Structure of Discussions within MyCourses.
Within the Submission Review area, setting availability dates will keep a discussion topic hidden from the students until the start date is reached and will hide it from the students until the end date passes. Within the Course Content area, the students will see the discussion topic but not be able to see the topics' directions or be able to access the topic. After the availability end date, students will no longer be able to access or view any posts within the Course Content area.
Within both the Submission Review and Course Content area, setting locking option dates will restrict students from posting to the discussion topic until the start date is reached and will not allow them to post after the end date. However, they will be able to see the discussion topic and its directions before the start date and allow students to view posts after the end date.
Which method to use:
It is up to you which one you want to use. You need to consider how you wish to use discussion topics within your class but having an understanding how each of these options behaves will help you make your decision. What is really important is that you do not use both options. Choose one or the other or none if you wish to keep your discussion topics open for the entire time. Setting both options will cause confusion on for both your students and you.