---
title: "Convert an optional block to tentative when its booking window opens."
method: PUT
path: "/booking/v0-nsfw/block-actions/{id}/start-optional"
tags: ["BlockActions"]
---

# Convert an optional block to tentative when its booking window opens.

`PUT /booking/v0-nsfw/block-actions/{id}/start-optional`

## Request

- Base URL: `https://api.apaleo.com` (the document declares no server; this is the origin it was published from)
- URL: `https://api.apaleo.com/booking/v0-nsfw/block-actions/{id}/start-optional`
- Auth: OAuth 2
  - Implicit: `https://identity.apaleo.com/connect/authorize`
  - Scopes: `blocks.manage`, `reservations.manage`, `admin`

Internal callback the scheduler invokes when an 'Optional' block's start timer fires. It releases the
block ('Optional' to 'Tentative'). A stale fire - the block already left 'Optional', or its stored
start no longer matches the payload - is a no-op.<br>You must have at least one of these scopes: 'blocks.manage, reservations.manage'.

## Path parameters

- `id` string, required

## Request body

- StartOptionalBlockModel
  - `expectedStartDateUtc` string, date-time, required: The block start timestamp the scheduler fired for. It is compared against the block's stored start so a stale or replayed callback (the start was moved, or the block already left 'Optional') is ignored.<br />A date and time in UTC or with UTC offset as defined in <a href="https://en.wikipedia.org/wiki/ISO_8601">ISO8601:2004</a>

## Response `204`

The callback was applied, or was a no-op for a stale fire.

## Other responses

- `400`: Bad request.
- `401`: You are unauthorized.
- `403`: Forbidden.
- `404`: The Request-URI could not be found.
- `415`: Unsupported media type.
- `422`: Validation errors in the request body or query params.
- `499`: Client closed request.
- `500`: An unexpected error occurred.
- `503`: The server is currently unavailable. Please try later.

---

[API](https://skmtc.dev/apaleo/apis/apaleo-booking-api-not-safe-for-work.md) - [All operations](https://skmtc.dev/apaleo/apis/apaleo-booking-api-not-safe-for-work/llms.txt) - [OpenAPI document](https://skmtc.dev/apaleo/apis/apaleo-booking-api-not-safe-for-work/revisions/a1b6a2f6b879?raw)