How far ahead should people be able to book?

Two limits, one at each end

Notice is how close to the appointment somebody may still book. With too little, a customer books a time that starts before anybody has read the email, and arrives to a locked door.

The horizon is how far ahead the diary is open. Too far, and you are taking bookings at prices and hours you have not decided yet, from people who may have forgotten by then.

Where a new project starts

Each is one setting on the booking rules screen, and suits most appointment businesses as it stands.

Choosing your own

• Shorten the notice when somebody watches the diary all day and a same-hour booking is welcome.
• Lengthen it when an appointment needs preparing: a room set up, notes read, something ordered in.
• Set the horizon to what you have decided. As far ahead as your hours, your staff and your prices are settled, and no further.
• Match the cancellation window to the notice you need to fill a slot again. A window of zero means customers always contact you to cancel.

How the limits are kept

• Only times between the two limits are offered, so a booking form never shows a time it would refuse.
• They are checked again when the booking is made. A time a page offered a while ago that has since slipped inside the notice is refused rather than booked.
• The horizon is counted from now. A new day opens as each one passes, with nothing to update.
• The rules are published to your website, so a form can say what it will not offer, and why, before anybody tries.

const rules = await bookings.settings();

rules.min_lead_minutes;              // notice, in minutes
rules.max_horizon_days;              // how far ahead
rules.cancellation_window_minutes;   // how late a customer may cancel

The business itself is never held to the cancellation window: you can cancel any booking from the dashboard at any time. Bookings has the rest of the rules, and How do you leave time between appointments? covers buffers.