It's not always convenient to allow a client to book an appointment for right now, before you've had a chance to fully prepare for them, and deliver them the level of service they expect. On the other hand, you don't want clients to be able to book appointments 7 months or even 10 years from now.
To solve these problems, use minimum notice periods and maximum scheduling windows. These two settings appear on each Appointment Type.
The minimum notice period is the earliest time in the future when a client can book an appointment. It's calculated from the time when the client views the appointment selection page, so you'll always have at least that much notice to prepare.
The maximum scheduling window is the furthest in the future where a client can book an appointment.
If either of these values is zero (the default value), TimeZest won't apply that particular limit to the potential appointment times it displays to clients.
Like all Appointment Type settings in TimeZest, they only affect scheduling requests created after the changes are saved, and won't affect scheduling requests already sent out.
A tip: If you have clients with multiple different SLAs, you might want to consider creating an Appointment Type for each SLA - so that those client paying for higher levels of service can select earlier times for their appointments.