Have you thought about having your calendar available at any time on your phone?
Medware Agenda is an application that allows the Physician to visualize his / her agenda of appointments and notify the patients in case there is some delay in the agenda.
With Medware Agenda the Physician has access to your calendar in real time, being able to select the day and time of day, has access to the detail of the appointment and the history of the patient.
It's very simple to have your calendar in your hands.