---
title: "Planetary Cycles"
method: POST
path: "/planetary-cycles"
tags: ["Calendar & Cycles"]
---

# Planetary Cycles

`POST /planetary-cycles`

Find all conjunctions between two planets within a date range, defining the start of a new synodic cycle.

## Request body

- PlanetaryCycles
  - `planet1Id` number, nullable, required
  - `planet2Id` number, nullable, required
  - `startDate` string, required
  - `endDate` string, required

## Response `200`

Successful calculation

- object
  - `ok` boolean
  - `data` object
    - `conjunctions` object[], nullable
      - `jd` number, nullable
      - `date` string, nullable
      - `planet1Id` number, nullable
      - `planet2Id` number, nullable
      - `longitude` number, nullable
      - `signIndex` number, nullable

## Other responses

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

## Changes

- **2026-08-24** `8ab5a768b521` — 1 warning, 4 info
  - removed the optional property `data/conjunctions/items/sign` from the response with the `200` status
  - added the optional property `data/conjunctions/items/jd` to the response with the `200` status
  - added the optional property `data/conjunctions/items/planet1Id` to the response with the `200` status
  - added the optional property `data/conjunctions/items/planet2Id` to the response with the `200` status
  - …1 more

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