---
title: "Wheel of the Year — True Astronomical Dates"
method: GET
path: "/calendar/astrology/cross-quarter"
tags: ["calendar"]
---

# Wheel of the Year — True Astronomical Dates

`GET /calendar/astrology/cross-quarter`

## Request

- Base URL: `https://api.openephemeris.com`
- URL: `https://api.openephemeris.com/calendar/astrology/cross-quarter`
- Auth: one of:
  - HTTP bearer
  - API key in header `X-OpenEphemeris-API-Key`
  - API key in header `X-API-Key`
  - API key in header `X-Service-Key`

Returns the 8 Wheel of the Year events (4 cross-quarters + 4 cardinal points) calculated using true apparent solar longitude from JPL DE440. Cross-quarter dates are the true midpoints between solstices and equinoxes, NOT the traditional Gregorian approximations. 🤖 AI-optimized output available — add `format=llm` to reduce payload ~45%. **Pricing:** 5 credits — one year, 8 events (the transit-search 1-year bracket).

## Query parameters

- `year` integer, required: Calendar year (Gregorian). Supported range: 1550–2649 (JPL DE440).
- `format` string, nullable

## Response `200`

8 Wheel of the Year events in chronological order

- CrossQuarterResponse: Solar events and cross-quarter days.
  - `_meta` object, required: Calculation metadata
  - `events` CrossQuarterEvent[], required: List of solar events in chronological order
    - `declination` number, required: Sun's declination at the time of the event
    - `distance_au` number, required: Sun's distance in AU
    - `name` string, required: Event name (e.g., Vernal Equinox)
    - `time` string, required: ISO 8601 UTC timestamp of exactly when the event occurs
    - `type` string, required: 'equinox', 'solstice', or 'cross-quarter'
  - `year` integer, required: Year of the events

## Other responses

- `400`: Bad Request
- `422`: Validation Error
- `500`: Internal Server Error

---

[API](https://skmtc.dev/openephemeris/apis/open-ephemeris-api.md) · [All operations](https://skmtc.dev/openephemeris/apis/open-ephemeris-api/llms.txt) · [OpenAPI document](https://skmtc.dev/openephemeris/apis/open-ephemeris-api/revisions/d195a769cb89?raw)