You can block off time in your calendar for personal events during opening hours so that people cannot book appointments when you're busy
There will be blocks of time where you won't want to book appointments with your Clients. This could be because you're doing something else you want to note in your calendar. Or if you've enabled the feature where your Clients are able to book their own appointments, you don't want to take appointments at that time. There are two ways to get this done:
If you want to block time on a permanent basis, it's a better idea to make a change to your operating hours. More info on updating operating hours.