Events with 0 duration are not visible on Day or Week view

An event with 0 duration (such as a due date from Assignments or Tests & Quizzes) will not be visible on the calendar in Day or Week view, even if you make sure the event is within the time frame shown. If you switch the view to Month, the events appear. 

This occurs with due dates from Assignments, Tests & Quizzes, and manually created events with a duration of 0 hours, 0 minutes.  These should be visible to instructor and students, even if the visual "length" of the event isn't accurate.