You can schedule your Challenge to start or end on a particular date and time. Once the Challenge has expired, the Challenge will no longer be available to the public.
Players can still view the Challenge, but they will not be able to complete it.
To add a start and end date to your Challenge, on the Topic Manager page, decide which Challenge you'd like to add an expiry date to, and click on it or on edit challenge.
Scroll down. Under the "Other Options" tab, you can add a start and expiry date to your Challenge.