For the case where a practitioner has different hours on the same day for different services, they can be set on the service.
An example would be a practitioner provides Adult services in the morning and Pediatric services in the afternoon.
On a service, click the "New Service Practitioner" button
Next to User, Click the "Lookup" button to select the practitioner
Next to Business Hours, Click the "Lookup" button to select the Business Hour