Would like to enter appt start and end times vs. fixed length time.

Is it possible to use Appointments+ and input a start time/end time for an appointment, vs a fixed time length? My client's scheduling needs the ability to do that.

For example, my client wants to use the plugin to schedule a sales call for 2 hours to demo a product. Does that mean he has to enter an appt multiple times? So for example, he wants to enter a 2 hour demo starting at 1:00pm, but the standard service time for a sales call is :30. Does he have to enter that 4 times?