---
title: "Update Week Start Day"
method: PUT
path: "/v1/auth/week-start"
tags: ["auth"]
---

# Update Week Start Day

`PUT /v1/auth/week-start`

## Request

- Base URL: `https://app.tokumalabs.com/api`
- URL: `https://app.tokumalabs.com/api/v1/auth/week-start`
- Auth: OAuth 2
  - Password
  - Token URL: `v1/auth/token`

Update which weekday the current user's calendars start on.

Display-only, and the desktop never reads the value from this
response: the write bumps ``users.version``, which replays the
synthetic ``user_settings`` row through the cursor sync feed on the
client's next round. The response exists so the caller can confirm
what was stored.

## Request body

- UpdateWeekStartDayRequest
  - `week_start_day` integer, required: First day of the week for calendar display: 0 = Sunday .. 6 = Saturday, matching JavaScript's Date.getDay(). Display-only; no server-side logic reads it.

## Response `200`

Successful Response

- UpdateWeekStartDayResponse
  - `week_start_day` integer, required: Updated first day of the week (0 = Sunday)

## Other responses

- `400`: Validation error or domain rule violation.
- `401`: Missing, expired, or invalid authentication.
- `403`: Authenticated but not permitted.
- `404`: Resource not found.
- `409`: Resource state conflict (duplicate, illegal transition).
- `422`: Request body failed schema validation.
- `500`: Server-side failure.

---

[API](https://skmtc.dev/tokumalabs/apis/tokuma-user-api.md) - [All operations](https://skmtc.dev/tokumalabs/apis/tokuma-user-api/llms.txt) - [OpenAPI document](https://skmtc.dev/tokumalabs/apis/tokuma-user-api/revisions/1f8201af459b?raw)