Avoid gaps in your schedule
Turn on Gap prevention in your booking settings and add buffer time to your services so customer bookings don't leave small gaps in your calendar. Both settings are set once and apply to every online booking after that.
Turn on gap prevention
Gap prevention filters the start times customers are offered so a booking doesn't leave a small gap in the calendar. It is off by default: until you turn it on, customers can book any start time that passes your ordinary availability and blocking rules.
Open Settings and go to Booking & availability.
In the Booking Settings panel, find Gap prevention.
Choose one of the six options: Off, Reduce calendar gaps, Back-to-back bookings (first booking unrestricted), Back-to-back bookings, Strict gap prevention (first booking unrestricted), or Strict gap prevention.
Save the setting, then open your public booking page and check which start times customers are offered.
Choosing a gap prevention level
All six options filter the start times customers are offered. The difference is how tightly they pack bookings against existing appointments and against the edges of the availability window.
Setting | What customers can book |
|---|---|
Off | Any valid start time, so small gaps between appointments are possible. |
Reduce calendar gaps | Start times spaced on a cadence based on the selected service's full blocked duration or your protected gap. |
Back-to-back bookings (first booking unrestricted) | Once an appointment exists in the window, only start times directly touching an existing appointment. On an empty day, every start time. |
Back-to-back bookings | Once an appointment exists in the window, only start times directly touching an existing appointment. On an empty day, only the first and last start times. |
Strict gap prevention (first booking unrestricted) | Once an appointment exists, start times touching an existing appointment or packed against the open edge of the window. On an empty day, every start time. |
Strict gap prevention | Once an appointment exists, start times touching an existing appointment or packed against the open edge of the window. On an empty day, only the first and last start times. |
Reduce calendar gaps
Reduce calendar gaps spaces the offered start times on a cadence based on the longer of the selected service's full blocked duration (duration plus buffer) or your protected gap. Your protected gap is the longest duration plus buffer across all your service variants, capped at 120 minutes.
Back-to-back bookings
The two Back-to-back bookings options place online appointments directly next to existing bookings. Once an availability window contains an appointment, the only offered start times are ones that touch it: the new appointment starts exactly when an existing appointment ends, or ends exactly when an existing appointment starts. A start time that sits against the open edge of the window without touching an appointment is not offered.
The two variants differ only on an empty day. Choose Back-to-back bookings if the first booking of the day should start only at the boundary of the availability window: the empty day then offers only the first and last start times. Choose Back-to-back bookings (first booking unrestricted) if the first booking may start anywhere: the empty day then keeps every start time. Once any appointment exists, both options offer the same times.
Strict gap prevention
Strict gap prevention also packs the day tightly. When an appointment touches or overlaps the edge of an availability window, only the start times packed against that appointment or against an otherwise open edge stay bookable, and the slots in the middle are removed. In an availability window with no appointments at all, only the first and last start times remain bookable.
Strict gap prevention (first booking unrestricted) behaves the same way once there is at least one appointment in the window, but in an empty window it keeps every generated start time. Pick this level if strict prevention fills too much of a quiet day for you.
The Strict gap prevention options are more permissive than the Back-to-back bookings options: they also keep the first and last start times that sit against an open window edge bookable, even when no appointment touches them. The Back-to-back bookings options hide those edge-only starts.
Examples
An empty day: a worker is available 9:00 to 17:00, the time slot interval is 30 minutes, and the service takes 60 minutes. Under Back-to-back bookings or Strict gap prevention, that empty day offers only 9:00 and 16:00: the first start sits against the opening edge of the window, and the last start finishes exactly at the closing edge. Under Back-to-back bookings (first booking unrestricted) or Strict gap prevention (first booking unrestricted), the same empty day offers every start time from 9:00 to 16:00.
A day with one booking: a worker is available 10:45 to 14:00, already has a booking from 10:45 to 11:30, and the service takes 60 minutes. Under both Back-to-back bookings options, the only offered start time is 11:30, directly after the existing booking. The 13:00 start finishes exactly at the closing edge, but it touches no appointment, so it is hidden. Under both Strict gap prevention options, 11:30 and 13:00 both stay bookable, because 13:00 sits against the open closing edge.
Salons that used strict gap prevention before it was split into two options keep the first-booking-unrestricted behavior. It changes only if the salon or a worker switches to the stricter Strict gap prevention option.
Each worker can also set their own level in My Preferences, under Booking Preferences. Leave it on Use salon default to follow the salon setting; a worker choice fully replaces the salon setting for that worker's calendar.
If a customer submits a time that is no longer valid under your settings, they see "That time is not available anymore, please choose another time." and return to time selection.
Gap prevention only filters customer bookings. Appointments you create yourself in the calendar are not checked against it.
Add buffer time between appointments
The Buffer field on a service variant adds blocked minutes after each appointment, for example for cleanup between clients. The customer still books what looks like the service duration, but the buffer blocks the worker's calendar and reduces how many start times fit in a window. Buffer also feeds the protected gap used by Reduce calendar gaps.
Open Services from the sidebar.
Open the service editor: select Edit service on desktop, or open the service menu and select Edit service on mobile.
Enter minutes in the Buffer field of the variant. Set it separately for each variant.
Select Save.
Buffer adds up: a 30-minute service with a 15-minute buffer blocks 45 minutes of the worker's calendar, and when a customer books several services their durations and buffers add together. A long buffer can also make a short availability window too short to book at all.
Gap prevention shapes which times customers can pick inside the availability you've opened, so see Setting Up Your Availability for opening those slots. For automatic professional assignment and the other booking controls, see the Smart scheduling guide.