Sun and Moon Almanac

Solar and lunar almanac offline: sunrise, sunset and twilight times, sun position and moon phase for any place and date - fully local.

Keyless — no signup, no API key, no environment variables.

Install

npx -y @mrfentmen/astronomy-mcp

Or add it to your MCP client:

{
  "mcpServers": {
    "astronomy-mcp": { "command": "npx", "args": ["-y", "@mrfentmen/astronomy-mcp"] }
  }
}

Tools

| Tool | What it does | |---|---| | solar_times | Sunrise, sunset, solar noon, civil twilight and day length for a place and date. | | sun_position | Sun altitude, azimuth, declination and subsolar point at an instant. | | moon_phase | Moon phase name, illumination, age in days, and the next full and new moon dates. |

Data source

NOAA solar position equations and low-precision Meeus sun/moon longitudes, computed locally