---
title: "Retrograde Periods"
method: POST
path: "/retrograde-periods"
tags: ["Calendar & Cycles"]
---

# Retrograde Periods

`POST /retrograde-periods`

Find all retrograde stations (direct, retrograde, stationary) for a planet within a date range.

## Request body

- Retrograde
  - `startDate` string, required
  - `endDate` string, required
  - `planetIds` integer[]

## Response `200`

Successful calculation

- object
  - `ok` boolean
  - `data` object
    - `periods` object[], nullable
      - `planetId` number, nullable
      - `planetName` string, nullable
      - `retroStart` string, nullable
      - `retroEnd` string, nullable
      - `stationRetroLong` number, nullable
      - `stationDirectLong` number, nullable

## Other responses

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

## Changes

- **2026-08-24** `8ab5a768b521` — 6 warning, 6 info
  - removed the optional property `data/periods/items/directLongitude` from the response with the `200` status
  - removed the optional property `data/periods/items/directStation` from the response with the `200` status
  - removed the optional property `data/periods/items/retrogradStation` from the response with the `200` status
  - removed the optional property `data/periods/items/retrogradeLongitude` from the response with the `200` status
  - …8 more
- **2026-08-23** `6828e5609564` — 1 breaking, 1 warning
  - the `planetIds/items/` request property type/format changed from `number`/`` to `integer`/``
  - the `planetIds/items/` request property's min was set to `0.00`

[Change history](https://skmtc.dev/astroway/apis/astroway-calculation-api/changes/retrograde-periods/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)