Steve: Hello I have an appointment with Dr Williams today.
Steve: But unfortunately I have to reschedule.
Clinic: OK, when would you like to come? 
Steve: is Wednesday available? 
Clinic: We have an open spot for 6 pm.
Steve: Perfect, please be so kind as to change my appointment to then.
Clinic: No problem. We will see you on Wednesday.
Steve: Thank you very much.
Steve can't visit Dr. Williams today. Clinic reschedules his appointment to Wednesday at 6 PM. 