You always have your phone with you and you have never used its embedded calendar. To the contrary, your colleague manages his own calendar in the office. A client calls you and asks you for an appointment. He is with another person essential to the meeting and must set an appointment immediately. It is 19:30 and your colleague has already left the office.

Fortunately, you can access the online calendar from your mobile. The appointment is set with your client and you can enter it in your calendar. Upon his arrival tomorrow morning, your colleague will be able to see this appointment and thus avoid an appointment collision.