Identify possible objects in the following systems and develop and object oriented design for them. You may make any reasonable assumptions about the systems when deriving the design.
A group diary and time management system is intended to support the timetabling of meetings and appointments across a group of coworkers. When an appointment is to be made that involves a number of people, the system finds a common slot in each of their diaries and arranges the appointment for that time. If no common slots are available, it interacts with the user to rearrange his/her personal diary to make room for the appointment.