In the past, when you added an assignment, under bulk edit -- there were little red dots in the calendar under the subsequent days that the class would be meeting. This was helpful to determine when to make an assignment due. Please bring back the red dots.
Interestingly, when setting the publish date for individual download and link items on a class bulletin board, the meeting dates are highlighted (as blue boxes) on the calendar. So there's extant code to do this very useful thing!