You can subscribe to your Blackboard calendar from within Google Calendar. Below is a video that shows how. Scroll down for written instructions.
Once you subscribe to your Blackboard calendar from within Google, new events in Blackboard will automatically sync to Google Calendar within an hour or so of being added to your Blackboard courses.
Link to video: http://goo.gl/IMtNLm
1. Go to Blackboard, click the "Home" tab, then click "Calendar"
2. Use the "Get External Calendar Link" button and copy the link to the clipboard
3. Go to Google Calendar at calendar.google.com
4. Next to "Other Calendars", click the dropdown and select "Add by URL"
5. Paste the link from Blackboard into the URL box and click "Add Calendar"
Your Blackboard calendar will be automatically synced to Google going forward.