Avoid Booking Same Time Slot

Is there a way to avoid booking in the same time slot? It seems multiple people can book within the same time slots. Maybe if there is a way to limit booking to 30 minute slots or one hour slots only, then mark those slots as not bookable.

We have bookings that overlap times on the same day. Example being if person-one books from 12:00 to 12:30 then another person can book 12:15 to 12:45 which is causing issues with scheduling.

Can we block out the time slots by 1/2 hour intervals?

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