---
title: "Calendar Round"
method: POST
path: "/mayan/calendar-round"
tags: ["Mayan Calendars"]
---

# Calendar Round

`POST /mayan/calendar-round`

Combined Tzolkin + Haab: unique date label within the 52-year cycle (18,980 days).

## Request body

- MayanDateOnlyInput
  - `date` string, required

## Response `200`

Successful calculation

- object
  - `ok` boolean
  - `data` object
    - `date` string, nullable
    - `julianDay` number, nullable
    - `calendarRound` string, nullable
    - `tzolkin` object, nullable
      - `number` number, nullable
      - `name` string, nullable
      - `label` string, nullable
    - `haab` object, nullable
      - `day` number, nullable
      - `month` string, nullable
      - `label` string, nullable
    - `description` string, nullable

## Other responses

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

## Changes

- **2026-08-24** `8ab5a768b521` — 9 info
  - added the optional property `data/date` to the response with the `200` status
  - added the optional property `data/description` to the response with the `200` status
  - added the optional property `data/haab/day` to the response with the `200` status
  - added the optional property `data/haab/label` to the response with the `200` status
  - …5 more
- **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/calendar-round/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)