What are the usability benefits of having 30-minute intervals for time slots when let's say, booking an appointment?
Less options makes it easier to choose one, which make it quicker to fill out a form with less effort. But only if that time option is sufficient for the user and only if it suits whatever it is for, obviously. The question needs far more ...
I assume you are booking appointment with a doctor or say car service maintenance.
To make most out of specialist time
Imagine your doctor works from 10:00 to 12:00, strict timing makes it possible to serve 4 patients.
If you allow random time booking there will be gaps and less patinets will be served.
Also most of the time there is no point in ...