2 kind of customer 1 schedule

if we have two type of customer :

A- Customer buying services online on marketing promotionnal site.

B- Regular customer.

Is it possible to have 2 différent schedule.

8 am to 9.30am ( 30 min session ) for customer A

10am to 16.30 pm for customer B

All of this shows on one schedule. could We blocked customer A to set an appointment on B schedule. Could we add a rules to obligate customer A to enter a Code to validate the appointment.

Thanks for your help