If you somehow stagger through office hours when you are late for valid reasons, you may begin arriving just as late on other days. In effect, arriving a half-hour late begins to be "on time." That's just courting trouble.
For your assistants, each working day becomes a race to process patients in less than sufficient time. For patients, the hurried treatment becomes a cause for dissatisfaction. Or else you take the time with earlier patients and make succeeding patients wait still longer.
There is only one solution to this problem, and it requires just one thing: your discipline. You have to be extremely faithful to your office hours starting times, or recognize your outside office demands and reset your office schedule. Courtesy to patients and staff-as well as good practice marketing-require this discipline.