The UpdateAppointment method initiates a callback command with the SchedulerCallbackCommandId.ClientSideUpdateAppointment identifier. It passes client appointment property values to the server, and updates a server Appointment counterpart of the specified client appointment.
A custom command should be inherited from the DevExpress.Web.ASPxScheduler.Internal.AppointmentClientSideUpdateCallbackCommand. Note that all client appointment properties, including custom fields, are passed with the callback as a string containing name:value pairs. Avoid using custom field names that duplicate standard appointment properties.