---
title: "Haab Civil Day"
method: POST
path: "/mayan/haab"
tags: ["Mayan Calendars"]
---

# Haab Civil Day

`POST /mayan/haab`

365-day civil calendar = 18 months × 20 days + 5-day Wayeb. Identifies if date falls in unlucky Wayeb period.

## Request body

- MayanDateOnlyInput
  - `date` string, required

## Response `200`

Successful calculation

- object
  - `ok` boolean
  - `data` object
    - `haab` object, nullable
      - `day` number, nullable
      - `month` string, nullable
      - `label` string, nullable
      - `isWayeb` boolean, nullable

## Other responses

- `400` — Validation error
- `401` — Missing or invalid API key

## Changes

- **2026-08-22** `5a17388652f3` — 1 breaking
  - added the new required request property `date`

[Change history](https://skmtc.dev/astroway/apis/astroway-calculation-api/changes/mayan/haab/post.md)

---

[API](https://skmtc.dev/astroway/apis/astroway-calculation-api.md) · [All operations](https://skmtc.dev/astroway/apis/astroway-calculation-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/astroway/astroway-calculation-api/revisions/8ab5a768b521/schema)