Western Moon Phase

Calculate the lunar phase for any date using the tropical zodiac. Returns phase name (New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Last Quarter, Waning Crescent), phase angle, illumination percentage, moon age in days, and next major phase estimate. Defaults to today if no date given.

Endpoint

GET /v1/western/moon/phase

Request parameters

Field	Type	Required	Description
date	string | null	No	Date in YYYY-MM-DD format. Defaults to today.

Example request

curl

curl -X GET "https://api.asterwise.com/v1/western/moon/phase?date=2026-01-01" \
  -H "Authorization: Bearer YOUR_API_KEY"

Python

import asterwise
from asterwise.api.western_astrology_api import WesternAstrologyApi

configuration = asterwise.Configuration(
    host="https://api.asterwise.com",
    access_token="YOUR_API_KEY",
)

with asterwise.ApiClient(configuration) as client:
    api = WesternAstrologyApi(client)
    result = api.western_moon_phase(date="2026-01-01")
    print(result)

TypeScript

import { createClient, createConfig, westernMoonPhase } from 'asterwise';

const client = createClient(createConfig({
  baseUrl: 'https://api.asterwise.com',
  headers: { Authorization: 'Bearer YOUR_API_KEY' },
}));

const result = await westernMoonPhase({
  client,
  query: {
      "date": "2026-01-01"
  },
});

console.log(result.data);

Example response

{
  "success": true,
  "message": "success",
  "data": {
    "date": "2026-01-01",
    "phase_name": "Waxing Gibbous",
    "phase_angle": 156.6555,
    "illumination_pct": 95.91,
    "moon_age_days": 12.85,
    "moon_longitude": 77.98827,
    "sun_longitude": 281.332736,
    "is_waxing": true,
    "next_phase_name": "Full Moon",
    "next_phase_date": "2026-01-03"
  }
}

Response fields

Field	Type	Description
success	boolean	True if the request succeeded
message	string	Human-readable status message
data	object
data.date	string	Date in YYYY-MM-DD format
data.phase_name	string	Current phase name
data.phase_angle	number	Phase angle in degrees (0-360). 0=New Moon, 180=Full Moon
data.illumination_pct	number	Percentage of Moon disk illuminated (0-100)
data.moon_age_days	number	Days elapsed since last New Moon (0 to 29.53)
data.moon_longitude	number	Tropical ecliptic longitude of Moon (0-360)
data.sun_longitude	number	Tropical ecliptic longitude of Sun (0-360)
data.is_waxing	boolean	True if Moon is waxing (phase_angle < 180)
data.next_phase_name	string	Name of the next major phase
data.next_phase_date	string | null	Estimated date of next major phase (YYYY-MM-DD)

Errors

Code	Description	Reference
authentication_failed	Missing or invalid API key.	authentication_failed
ephemeris_unavailable	Upstream ephemeris service error.	ephemeris_unavailable
insufficient_tier	API key tier does not include this endpoint.	insufficient_tier
internal_error	Unexpected server error.	internal_error
ip_rate_limit_exceeded	Too many requests in a short window.	ip_rate_limit_exceeded
payload_too_large	Request body exceeds the size limit.	payload_too_large
resource_not_found	Referenced resource was not found.	resource_not_found
validation_error	Request body failed schema validation.	validation_error

Related endpoints

• Biorhythm Cycles
• Western Moon Phase Calendar