Think of it as a 24 hour day that starts at (to use UK public transport's setup) 4:30. You want the timetable and the users to agree on what 8am means, and that

Think of it as a 24 hour day that starts at (to use UK public transport's setup) 4:30. You want the timetable and the users to agree on what 8am means, and that 8am and the following 2am are the same work day of 24 hours.