Nager.Date MCP Server

MCP server wrapping the Nager.Date API — public holidays for 202 countries with local names, types, long weekends, and regional subdivisions.

Tools

• get_holidays(country, year?, type?, county?) — All holidays for a country/year. Filter by type (Public, Bank, School, Observance, etc.) or subdivision (e.g. GB-SCT, DE-BY). Includes day-of-week.
• get_next_holidays(country, county?) — Upcoming holidays from today forward.
• get_long_weekends(country, year?) — Long weekends with bridge day suggestions.
• is_today_holiday(country, county?, offset?) — Quick yes/no: is today a public holiday? Optional UTC offset for timezone.
• list_countries(query?) — All 202 supported countries; optional case-insensitive substring filter on name/code.
• get_country_info(country) — Country metadata: official name, region, borders.
• get_worldwide_holidays() — Every holiday happening today, globally.

Return shape convention

get_holidays and get_next_holidays normally return a plain list of holiday objects. When a filter produces a result that could mislead, they instead return a dict {"holidays": [...], "note": "..."} where note explains the caveat:

• A type filter matched no holiday (the country may use a different type label).
• A county filter matched no regional holiday, so only national/global holidays are shown (often a typo'd subdivision code).

LLM consumers should handle both shapes: if the result is a dict, surface the note and read the holidays from result["holidays"]; if it's a list, use it directly. Error and no-data cases return a plain string message.

Features

• No API key required — uses the free public API
• In-memory TTL cache (24h for static data, 1h for "next" endpoints, 7d for country info)
• Country code normalization (lowercase accepted)
• Day-of-week enrichment on all holiday results
• Client-side filtering by holiday type and subdivision
• Friendly error messages (no crashes on invalid input, including valid-format country codes the API has no data for)

Install

cd nager-date-mcp
pip install -e .

Configure (Hermes)

Add to your Hermes config.yaml under mcp_servers:

mcp_servers:
  nager-date:
    command: python
    args: ["-m", "nager_date_mcp.server"]

Or for Claude Desktop / other MCP clients:

{
  "mcpServers": {
    "nager-date": {
      "command": "python",
      "args": ["-m", "nager_date_mcp.server"]
    }
  }
}

Development

pip install -e ".[dev]"
python -m pytest tests/ -v

API Details

• Source: https://date.nager.at/api/v3/
• Auth: None
• Rate limits: None observed (Cloudflare CDN, 7-day cache headers)
• Year range: 1976–2076
• Countries: 202 (ISO 3166-1 alpha-2)
• Subdivisions: ISO 3166-2 (e.g. GB-ENG, GB-SCT, DE-BY, CA-ON)
• Holiday types: Public, Bank, School, Authorities, Optional, Observance