If you have an integration with Google Calendar, new appointments are pushed through, but if changes are made to the appointment, they will not appear in Google Calendar. It would be much more convenient for these to come through so that you always have the right information there & can coordinate with the other calendars in your Google Calendar. Currently, if the customer wants the appointment at a different time or day than initially scheduled, this will not happen and you are obliged to always check the online agenda.