What are reliable alternatives to Holiday Calendar?

Measured by Faceabot as working: Business Day Calendars.

How do I connect an AI agent to Holiday Calendar?

Use the MCP streamable HTTP endpoint https://starter.modernmustardseed.com/holidays.

Catalog › com.modernmustardseed/holiday-calendar

Is Holiday Calendar reliable?

Reliable (measured) Yes. Faceabot measured Holiday Calendar 26 times: 100% of checks succeeded, including the last 26 in a row (last check 2026-10-19 21:40 UTC). It also does the job: its real read-only task worked 26 of 26 times.

Last check: 2026-10-19 21:40 UTC · answered in 7175 ms · remote (no install)

En français : Fiable (mesuré). Faceabot teste cet outil lui-même, en continu, sans dépendre de ce que son auteur affirme.

What it does

U.S. federal holidays with observed dates and business-day math. Example from an open-source kit.

Source: official MCP registry (registry.modelcontextprotocol.io) · version 1.0.1 · publisher website

Connect your agent

{
  "mcpServers": {
    "holiday-calendar": {
      "url": "https://starter.modernmustardseed.com/holidays"
    }
  }
}

Or ask Faceabot first: MCP tool check_reliability {"id":"com.modernmustardseed/holiday-calendar"} on https://faceabot.com/api/mcp.

Does it actually do the job?

Does the job (tested) — Faceabot asked next_federal_holidays to do a small read-only task 26 time(s): 26 returned a real result, the last 26 in a row. Last result: ok in 4432 ms.

Sample input: {}. A success means a non-empty result without error; it does not certify the accuracy or safety of the content.

Other proven tools for the same job

Business Day Calendars Reliable (measured) · 100%
NYSE, Federal Reserve, TARGET2 and UK business days, holidays and T+N settlement dates. · https://business-days.quietworklabs.workers.dev/mcp

Picked from Faceabot's live measurements. Or let Faceabot choose: GET https://faceabot.com/resolve?need=…

Faceabot measurements

When	Answers	Real task	Latency
2026-10-19 21:40 UTC	✅ ok	✅ done	7175 ms
2026-10-19 09:10 UTC	✅ ok	✅ done	6497 ms
2026-10-18 16:15 UTC	✅ ok	✅ done	7100 ms
2026-10-18 05:05 UTC	✅ ok	✅ done	8526 ms
2026-10-17 21:10 UTC	✅ ok	✅ done	7150 ms
2026-10-17 12:40 UTC	✅ ok	✅ done	6318 ms
2026-10-17 04:55 UTC	✅ ok	✅ done	6535 ms
2026-10-16 21:15 UTC	✅ ok	✅ done	4825 ms
2026-10-16 14:05 UTC	✅ ok	✅ done	6411 ms
2026-10-16 07:05 UTC	✅ ok	✅ done	6045 ms
2026-10-16 00:10 UTC	✅ ok	✅ done	7244 ms
2026-10-15 17:16 UTC	✅ ok	✅ done	8694 ms
2026-10-15 10:31 UTC	✅ ok	✅ done	4097 ms
2026-10-15 03:55 UTC	✅ ok	✅ done	3586 ms
2026-10-14 21:30 UTC	✅ ok	✅ done	8144 ms
2026-10-14 15:00 UTC	✅ ok	✅ done	5442 ms
2026-10-14 08:35 UTC	✅ ok	✅ done	4200 ms
2026-10-14 01:51 UTC	✅ ok	✅ done	7881 ms
2026-10-13 19:40 UTC	✅ ok	✅ done	8558 ms
2026-10-13 13:35 UTC	✅ ok	✅ done	8275 ms

Method: MCP initialize then tools/list from Faceabot (FaceabotProbe/1.0), plus one read-only tool call with a neutral input when the server declares one, repeated over time. This checks that the server is up and speaks MCP correctly; it does not certify the quality or safety of each tool. How measurement works.

More from the same publisher

AI Search Kit Flaky · 89% over 9 checks Does the job (tested) · 8/8

Audits AI-crawler access, structured data and llms.txt on a site, and drafts the fixes.

MCP endpoint : https://mcp.modernmustardseed.com/ai-search-kit · website · measurements and details

Call Desk Flaky · 89% over 9 checks Does the job (tested) · 8/8

US and Canada calling rules: number checks, calling hours, recording consent, AI voice disclosure.

MCP endpoint : https://mcp.modernmustardseed.com/call-desk · website · measurements and details

Chief Dreamer Private (key required)

A private, persistent memory and method for your dreams and ideas. Sign-in required (OAuth).

MCP endpoint : https://dreamer.modernmustardseed.com/mcp · website · measurements and details

Domain Health Reliable (measured) · 100% over 26 checks Does the job (tested) · 26/26

Domain checks: SPF, DKIM, DMARC, BIMI, MTA-STS, SSL/TLS and HTTP security headers.

MCP endpoint : https://mcp.modernmustardseed.com/domain-health · website · measurements and details

Dry Run Reliable (measured) · 100% over 26 checks Does the job (tested) · 26/26

Monte Carlo cash-flow simulator for a small services business: odds of running short, and why.

MCP endpoint : https://mcp.modernmustardseed.com/dry-run · website · measurements and details

Publisher of Holiday Calendar?

Show your measured reliability on your README or website:

[![Measured by Faceabot](https://faceabot.com/badge/com.modernmustardseed/holiday-calendar.svg)](https://faceabot.com/tools/com.modernmustardseed/holiday-calendar)

Data in JSON: /api/catalog?id=com.modernmustardseed/holiday-calendar · Stop probes: POST /api/reliability/opt-out

AI agents: all of this is available without keys over MCP https://faceabot.com/api/mcp · HTTP https://faceabot.com/api/catalog?q=… · Guide : llms.txt

Best tool by topic · Pulse: what is changing in agent commerce · Is your store ready for AI shopping agents? · State of MCP (weekly) · MCP server doctor · Reliability data · Faceabot app · Faceabot → AI assistants · What AI agents cannot find yet · Add Faceabot to your AI · Badge for tool publishers · Help · Privacy · Terms