Moodle 2.2.5.
A quiz is started by a student. Start time is recorded. Time taken displays "open".
Student does not click finish attempt but answers questions.
Student navigates away from the quiz or browser crashes or connection fails before attempt time elapses.
Student accesses the quiz and summary displays "In progress" in the summary of previous attempts.
Student does not make another attempt on the quiz.

Result:
Quiz remains in open state indefinitely.
Teacher reviews attempt which displays "attempt in progress".
Teacher cannot force the attempt to close.

If Student accesses the quiz and clicks the "Continue the last attempt" button, the quiz attempt moves to completed state and in review mode.
Overdue time is listed.

In other conditions such as the quiz being in open state and attempt time expires while student is still in the quiz, the attempt is finished automatically. Same situation if the close date/time expires while student is still in the quiz.

Apparent fix is scheduled for version 2.3 but it would be nice to have a cleaner way to close such attempts without needing the student to access the quiz to have it role over from open to completed state.

Related tracker issues: MDL-24814, MDL-15772

Quiz override would need to be used.