---
title: "Add an extra date (Occurrence) to a repeating schedule"
method: POST
path: "/signups/{id}/slot_series/{seriesId}/occurrences"
tags: ["Slots"]
---

# Add an extra date (Occurrence) to a repeating schedule

`POST /signups/{id}/slot_series/{seriesId}/occurrences`

## Request

- Base URL: `https://thesignup.app/api/v1`
- URL: `https://thesignup.app/api/v1/signups/{id}/slot_series/{seriesId}/occurrences`
- Auth: HTTP bearer

Add one Shift on one date of the signup's Slot Series: `seriesDate` (`YYYY-MM-DD`, inside the Series' range), `start` / `end` (`HH:MM` in the signup's timezone), and optionally `label`, `capacity` (default: the Series' own) and `location`. The new Occurrence is detached from birth: it does not follow the rule, so a later Series edit leaves it alone, and the dates the rule generates are unchanged. On a date the rule already generates it becomes a second Occurrence at the next `shiftIndex`. A date outside the Series' range, or an `end` not after `start`, is `400 bad_request` and nothing is written. Adding a date notifies nobody. `location` is behind a pre-GA rollout for the person an OAuth token acts as (`403 forbidden` when they are outside it); an API key is not checked.

## Path parameters

- `id` string, uuid, required
- `seriesId` string, uuid, required

## Request body

- AddOccurrenceRequest
  - `seriesDate` string, required: The date to add the Occurrence on, `YYYY-MM-DD`, inside the Series' range.
  - `start` string, required: `HH:MM` wall-clock start in the signup's timezone.
  - `end` string, required: `HH:MM` wall-clock end in the signup's timezone, after `start`.
  - `label` string: The Shift's name. Absent leaves it untitled.
  - `capacity` integer: Spots. Absent takes the Series' own capacity.
  - `location` string, nullable: The Occurrence's place. Absent resolves through the Series' default, then the signup's.

## Response `201`

The new Occurrence

- OccurrenceResponse
  - `slot` Occurrence, required
    - `id` string, uuid, required
    - `eventId` string, uuid, required
    - `startTime` string, date-time, required
    - `endTime` string, date-time, required
    - `maxParticipants` integer, required
    - `maxPerPerson` integer, required: The most spots one person may take on this slot. 1 (the default) is one spot per person; 0 is no per-person limit.
    - `title` string, nullable, required
    - `description` string, nullable, required
    - `location` string, nullable, required
    - `customField` object, nullable, required: The slot's own question, as stored. Read `question` for what the slot actually asks — a slot generated from a repeating shift may inherit the shift's question when this is null.
      - `name` string, required
      - `placeholder` string
      - `required` boolean, required
      - `type` 'short' | 'long', required
    - `question` object, nullable, required: The question participants are asked when taking this slot: the slot's own, else the repeating shift's. Null when nothing is asked.
      - `label` string, required
      - `placeholder` string: Example answer, shown as a hint in the answer box. Absent when none was given.
      - `required` boolean, required
    - `questionSource` 'own' | 'series' | 'null', nullable, required: "own" when `question` is the slot's own; "series" when inherited from its repeating shift; null when nothing is asked.
    - `createdAt` string, date-time, required
    - `seriesId` string, uuid, required
    - `seriesDate` string, required: The date the rule generated this Occurrence for, `YYYY-MM-DD`.
    - `shiftIndex` integer, required: Position in the Series' shift plan. `(seriesId, shiftIndex)` is the Shift.
    - `detached` boolean, required
    - `cancelledAt` string, date-time, nullable, required: When the Occurrence was cancelled, or null while it is live. A cancelled Occurrence keeps its registrations.

## Other responses

- `400`: Bad request — body or path could not be parsed
- `401`: Unauthenticated — credentials missing, malformed, invalid, or revoked
- `403`: Forbidden — credentials valid but lack the required scope
- `404`: Not found
- `422`: Validation failed — request body / query / path is structurally wrong
- `429`: Rate limited or daily ceiling exceeded
- `500`: Internal server error

---

[API](https://skmtc.dev/thesignup/apis/thesignup-api.md) · [All operations](https://skmtc.dev/thesignup/apis/thesignup-api/llms.txt) · [OpenAPI document](https://skmtc.dev/thesignup/apis/thesignup-api/revisions/c6da7cf92172?raw)