Your Blackboard course is your virtual classroom and YOU hold the key. When you are ready to enable student access to your virtual classroom, simply "unlock" it by making it available. When you do so, the course will be available to students beginning 2 weeks before the first day of classes for the term. Why?
Available courses automatically become unavailable to students four weeks after the last day of classes for the term. You (instructors) have access to all of your Blackboard courses. On the Control Panel menu at lower left, click Customization > Properties.