Length, gaps and slot times
How long an appointment takes, the gaps around it, and why times appear where they do.
Three settings decide when a customer can start an appointment: how long the service runs, how much protected time follows it, and the grid every start time sits on. Two live on the service; the third is site-wide. A fourth, the least notice you take, decides how soon the first time can be.
Length: how long one appointment runs
Length lives in the Time and money card on the General tab of any service, under Services. It is a whole number of minutes, and a new service starts at 30. It sets the length of the block drawn in your Diary, and how much clear time a slot must find before that start time can be offered.
On the customer's service card it is written the way people speak — "45 min" under an hour, then "1h 30m" or "2h".
The box accepts 1, but when Booked works out which times to offer, anything under five minutes is treated as five.
If the service allows Group bookings, party size multiplies the length. Three people on a 20-minute service is one 60-minute appointment with one member of staff — not three running side by side. That is why times can disappear when a customer adds a second person.
Gaps: only one of them reserves time
The same tab holds two more boxes. They look like a matching pair. They are not.
How long it takes, what it costs, and what is taken up front.
The General tab of a service — length (1) and the two gap boxes (2, 3).
- 1Length — how long one appointment runs, and the length the customer is quoted.
- 2Gap before — saved and shown back to you (the Services list reads it as “+0 / 10 buffer”), but never used. It has no effect on which times are offered.
- 3Gap after — the one that does the work. It is added to the length, so a slot must find length plus gap of clear time.
If you need ten minutes to clean the room before an appointment, typing 10 into Gap before changes nothing. Add it to Gap after instead, or lengthen the length.
The gap is not written into the saved appointment's end time — the diary block still shows 30 minutes, not 40. What it does is make Booked look for 40 clear minutes running forward from the start time before it will offer that time at all. So it protects the run-up to your next booking, but a customer can still take a slot starting the exact minute an existing appointment finishes. Two 30-minute appointments with a 10-minute gap can end up genuinely back to back. And when staff book by hand in the Diary or Bookings, times are checked for that booking’s own Length only; the gap is not added.
The time slot interval sets the start grid
Length and gap decide how much room an appointment needs. The Time slot interval decides where it may begin. It lives at Settings › Booking rules, in the Taking a booking card.
How far ahead people can book, how fine the slots are, and what happens the moment a booking lands.
The steps the booking form offers times in. Finer steps fill gaps; coarser ones keep the diary tidy.
Settings › Booking rules (1), where the Time slot interval (2) is set for the whole site.
- 1Booking rules — rules that apply to every booking, whatever the service. The interval sits in the Taking a booking card, beside the least notice you take and whether bookings are approved by hand.
- 2Time slot interval — 5, 10, 15, 20 or 30 minutes, or 1 hour. The default is 15. It changes only where an appointment can start, never how long it is.
Two details catch people out. Start times are stepped from the beginning of each open period, not from the clock — a branch opening at 09:10 on a 15-minute interval offers 09:10, 09:25, 09:40, not 09:15. And the whole block must fit inside one continuous open period, so an appointment can never straddle a lunchtime close or run past closing time.
Worked example: a morning ear-care clinic
Priya runs ear syringing at the Bramhall branch on Tuesday mornings, 09:00 to 13:00. The service is 30 minutes with a 10-minute gap after, on the default 15-minute interval.
A 30-minute service with a 10-minute gap, on a 15-minute grid, in a 09:00–13:00 clinic.
- 1The open period — where the branch is open and Priya is working. Every block must sit entirely inside it.
- 2The block — 30 minutes of appointment plus 10 minutes of gap. Booked needs 40 clear minutes before it offers a start time.
- 3The last start of the morning — 12:15. A 12:30 start would need until 13:10, and the clinic closes at 13:00.
- 4What the customer is offered — every quarter hour from 09:00 to 12:15. 12:30 and 12:45 never appear.
Notice what the gap costs. Without it, a 12:30 start would finish exactly at 13:00 and be offered. With it, 12:30 would need until 13:10, so it disappears — and because starts only exist on the quarter hour, the last bookable time drops back to 12:15. You lose a whole appointment off the end of the morning, not ten minutes. That is the price of protecting your turnaround.
Matching the interval to your lengths
The interval is one setting for the whole site, so it needs to suit your commonest appointment length. When a length is not a multiple of the interval, dead gaps open between back-to-back bookings.
| Length | Interval | What happens |
|---|---|---|
| 30 min | 15 minutes | Appointments sit flush against each other. Nothing wasted. |
| 45 min | 15 minutes | Also clean — 45 divides by 15. |
| 20 min | 15 minutes | 09:00–09:20 is booked, and the next offerable start is 09:30. Ten minutes of every cycle is unusable. |
| 20 min | 20 minutes | The same service, back to back all day, with no gaps. |
| 10 min | 1 hour | One start an hour. Fifty minutes idle between appointments. |
A 5-minute interval gives the most choice and packs the day tightest, but produces ragged times like 09:35. A long interval keeps the diary tidy at the cost of bookable time.
Changing Time slot interval moves the start times for every service, branch and member of staff, on the booking form and in the admin. Existing bookings keep their old times, so change it when the diary is quiet.
If the times aren't where you expect
- The last slot of the day is earlier than you thought. That is Gap after pulling the last start back so the whole block still fits before you close.
- Times start at odd minutes, like 09:10. The grid counts from the start of your open period, not from the hour. Check the branch opening hours and the staff working hours.
- There is a hole between every appointment. Your length is not a multiple of the interval. Change one so they divide evenly.
- Times vanished when the customer added a person. Group bookings multiply the length, so three people on a 20-minute service need a clear hour.
- You changed "Gap before" and nothing happened. It does nothing. Move the minutes to Gap after.
- Today’s first times, or all of today, are missing. That is the least notice you take, not the length. See below.
- No times at all on a day. This is rarely length or gaps. Check the branch has opening hours, someone is working, a member of staff is linked to both the service and that branch, and the service’s Availability tab allows that day.
How soon a customer can book
Past times always drop off today’s list. To keep customers further back than that, use Least notice you’ll take, the first box in the same Taking a booking card. Enter a number and pick minutes, hours or days. It starts at nothing, and the most it will take is four weeks. Underneath, Booked says what your figure means right now, for example “Asked right now, the soonest a customer could book is 09:45 today.”
- It is a moment, not a day. Six hours’ notice asked at 22:00 lands at 04:00 the next morning, so it trims the start of tomorrow rather than blocking the whole of it.
- It applies to customers only. Staff booking in the Diary are never held to it, so someone at the counter can still be booked in for ten minutes’ time.
- One service can differ. On a service’s General tab, Least notice for this service reads Same as the rest of the site — 1 day (showing your figure) or Something different for this service, which opens its own number and unit. A walk-in flu jab can need none while a travel consultation needs a day.