Some assignments may be used for tests and so they need to remain hidden from students until the right time. Firefly will automatically unhide an assignment if you set it as a task.
Choose who can see your page by setting the visibility on your page. You can effectively hide the page from the students until you are ready to set it.
When you want to set the task, return to your assignment page and choose Set this assignment as a task to a group
You will be prompted to confirm that you would like the hidden assignment to now be accessible by the group you are setting the task to.
Select Publish Task to unhide your assignment.