Until the new Appointment Details page, a client could only confirm their appointment via reminder email or text. Since reminders can only go out in the 5 days leading up to the appointment, clients were only able to confirm within that window.
On the new Appointment Details page, clients saw the option to confirm their appointment at any time after booking. We heard your concerns that some customers were confirming too far in advance.
To address this, we have hidden the ability to confirm until clients are within the time frame during which they would receive their first reminder.
You don't have to change anything on your end to put this change into effect, but if you'd like to review your reminder settings you can do so under the Details section of the Manage Location settings.