Moodle 3.2 introduces a discussion locking option for forums—but don't get too excited yet.... this does not mean that we can set due dates for posting to a forum. :-(
If you enable the locking function, individual discussion threads will close down after a set period of inactivity—the forum as a whole will remain open to continued participation, but any thread that hasn't had a response made to it after that time will be shut off from new posts. The image at right shows what students would see once a discussion thread closes.
We don't recommend enabling this function unless you have a compelling need.