> ## Documentation Index
> Fetch the complete documentation index at: https://docs.uplifter.app/llms.txt
> Use this file to discover all available pages before exploring further.

# How do booking slots and capacity work?

> How free slots are computed from availability minus reservations, and how capacity fills a slot.

<Note>
  **Must know**

  * Available on plans that include **Bookings** (defaults off) — if you don't see it, ask your Uplifter contact.
  * A blank capacity means **unlimited** — a slot is only full once the confirmed attendees reach the cap.
  * **Pending-approval** reservations hold no slot and don't count toward capacity until you approve them.
</Note>

When a member picks a date, Uplifter shows the times that are actually free. It starts from your weekly **availability** windows for that day and subtracts any **confirmed** reservations that overlap.

**Only within the booking's dates.** A member can pick dates inside the booking's Start Date–End Date window only. A date before it opens or after it ends shows no times, and once the End Date has passed the booking comes off your public site entirely.

**Fixed-duration bookings.** If you set a duration (and optional buffer), Uplifter generates a grid of valid start times — window start, then each following slot spaced by the duration plus buffer. Only times on that grid can be booked; an off-grid time is rejected, so members can't slip in between slots.

**Variable-window bookings.** With no fixed duration, the raw availability window is offered and confirmed reservations are blocked out of it.

**Capacity is attendee-count aware.** Capacity counts people, not reservations. A slot is full only when the summed attendee count across overlapping confirmed reservations reaches the cap. So a slot with a capacity of 6 can hold one reservation for 4 plus another for 2. With capacity left blank, the slot never fills.

**What counts, and when.** Only **confirmed** reservations reduce availability and count toward capacity. A reservation that's waiting for approval is invisible to the slot math until you approve it — at which point capacity is re-checked before it's confirmed.

**Related:** [How do I create a bookable space or lesson?](/club/events-competitions/create-a-bookable-space-or-lesson) · [Review and approve booking reservations](/club/events-competitions/approve-booking-reservations) · [How are bookings priced and paid for?](/club/events-competitions/how-bookings-are-priced-and-paid)