Create two appointment slots at set times for one service

Hi there, 

I want to have people sign up for a two hour training either at noon or at 3.15 pm without options to sign up for a later time then the starting time. Right now I have the following settings installed. The problem is that people can sign up for different times during the time slot, sign up for an appointment during non-business hours (14.00/ 2 pm) and the 3.15 pm timeslot changes to 3 pm.

Is there a way to create two sign up times (at 12 o'clock and 3.15 pm) in one day for one service?

Bookings page

Duration: 1 hour 30 minSpecific availability between datesGeneral availability