Bookings API Fetching Availability

Bookings API Fetching Availability

I'm using zoho bookings and created a 45 minute drop-in Yoga class that is every M/W/F at 9am and 2pm run by staff member John.
When I send a request to fetch availability using these settings:
Request URL: https://www.zohoapis.com/bookings/v1/json/availableslots
Service_ID: ID for Yoga
Staff_ID: ID for John

It returns every single timeslot that John is available for the day (9:00, 9:15, 9:30, 9:45, 10:00, etc). I need it to just return 9am and 2pm, because that's the only time the class is available. 

I'm basically trying to find all available classes for a single day. How can I accomplish this?