Void-of-Course Moon
asterwise_get_western_void_of_course_moon
Lists void-of-course Moon periods in a date range (UTC), each with start, end, duration, the Moon's sign, the next sign and the last exact aspect. Rule: traditional — the Moon is void from its last exact Ptolemaic aspect (conjunction, sextile, square, trine, opposition) to the Sun, Mercury, Venus, Mars, Jupiter or Saturn until it enters the next sign (Lilly, Christian Astrology 1647, p. 112). Outer planets are not counted.
Parameters
| Parameter | Type | Required | Description |
|---|---|---|---|
from_date | string | yes | Start of the date range, YYYY-MM-DD (inclusive). |
to_date | string | yes | End of the date range, YYYY-MM-DD (inclusive). |
response_format | enum: markdown, json | no | Output format: 'markdown' (default) for a readable report, or 'json' for the raw structured payload. |
What it covers
Tropical (Western) void-of-course Moon tables for planning: one period per Moon sign passage (about every 2.5 days). No birth data needed.
Workflow
BEFORE: None — standalone.
AFTER: asterwise_get_western_planetary_hours — pick an hour inside a non-void window.
Input
from_date (string YYYY-MM-DD, UTC) — first day of the range.
to_date (string YYYY-MM-DD, UTC, inclusive) — last day; at most 92 days after from_date.
Output contract
data.from_date, data.to_date, data.definition (string — the rule in plain English)
data.periods[] — each:
start_utc, end_utc (string — ISO 8601 UTC with Z)
duration_hours (float)
moon_sign, moon_sign_index, next_sign, next_sign_index
last_aspect (object or null — planet, aspect, exact_at)
whole_sign_void (bool — true when the Moon made no exact aspect in that sign)
Response format
response_format=json — structured periods. response_format=markdown — readable table.
Compute class
MEDIUM_COMPUTE
Errors
INVALID_PARAMS (upstream): bad dates, to_date before from_date or a range over 92 days → 422, surfaces as MCP INTERNAL_ERROR with the API message.
INTERNAL_ERROR: Any upstream API failure → MCP INTERNAL_ERROR
Do not confuse with
asterwise_get_western_moon_phase — phase (new/full), not void periods.
asterwise_get_transits — sign ingresses for all planets, no aspects.
Connect
Remote MCP endpoint: https://mcp.asterwise.com/mcp. Authenticate with Authorization: Bearer <API key> or OAuth. See the MCP setup guide.