Yes, you can do this. Be careful what you wish for. 😉
If you hide it, you have to remember to make it available. And when your students call the help desk, we’re just going to refer them to you!
Go into the Control Panel, Customization, Properties.
Go to item #3. The default is “yes” which means the course is available.
Set it to “no” to turn off ALL access. Students can’t see Announcements or anything; just that the course is not available. IMPORTANT: If you turn it off, it stays off until you turn it back on.
Or select “use term availability” which is set to August 23, the Thursday before classes start. At least you don’t have to remember anything.