Currently a teacher can toggle visibility for at task manually, but not timed.
This might not have been a problem if not for the possibility for students to see the description of a task before they are able to actually start a task.
If a student opens a task, they have not yet started (before or after the start time) it shows this view:
If the student then hit the "Close" button they will be able to see the text of the assignment (again even if it is before the start time)

Currently a teacher can toggle visibility for at task manually, but not timed.
This might not have been a problem if not for the possibility for students to see the description of a task before they are able to actually start a task.
If a student opens a task, they have not yet started (before or after the start time) it shows this view:
If the student then hit the "Close" button they will be able to see the text of the assignment (again even if it is before the start time)