A recent change to Moodle now provides the opportunity to schedule forum posts.

This now means that if you want an announcement to be sent to your students at a particular time then you no longer have to log in to Moodle at that specific time to send it!
I’ve recently written an article on TELSupport which explains the steps to take if you want to take advantage of this feature: How do I schedule announcements in my Moodle course?