They would prefer that the patient can't see the time allowed for their appointment when booking it online from the Portal. It happens that some patient insisit on spending the exact amount of time with th doctor even though he feels it is not necessary. Also, for a 30 min consult in the calendar, the doctors will often spend 5 minutes before consulting the medical history and an additionnal 5 min at the end to complete the note, so a 30 min appointment means 20 min with the patient.