On your Blackboard course, select +  and Tool Link to begin adding the calendar tool to the menu:

Choose Calendar from the drop down menu, and check the box to make it Available to Users.

Course items with due dates appear  automatically in the course calendar (e.g. tests and assignments), if you have specified these.  Common entries include upcoming tests, due dates for  assignments, or special lectures.

If you want to add a deadline for another event  you can manually add the event. Click on the day of the deadline in the calendar :

Provide the details. You can assign the event to a module using the drop-down link. It is set by default to the module of the Blackboard course you are viewing.

Course calendar events appear to all members of  the course. Only instructors can create course calendar events.