Koskamo

Japan Business Calendar MCP

A remote MCP server providing Japanese business day calculations, holiday checks, and invoice due date computations for AI agents. It supports free access to next holiday queries and paid access for business-day math and year planners, utilizing data from the holidays-jp API based on Cabinet Office schedules.

Endpoint and access

No sign-in to connect and list tools. Individual tools may still need a vendor account, credentials, or permissions; check the documented prerequisites.

Japan Business Calendar MCP logo, by Donnie MorrisonCommunity listingStreamable HTTPNo sign-inEndpoint checked 2026-11-01Published by Donnie Morrison
MCP endpoint (Streamable HTTP)
https://jp-business-calendar-mcp.donniertf.workers.dev/mcp
Vendor documentation

What you can do with it

  • Check next 3 Japanese public holidays and if today is a business day
  • Add or subtract N Japanese business days from a specific date
  • Calculate invoice due dates based on calendar or business days
  • Retrieve full Japanese holiday list for a specific year

Source and maintenance

Community listingRegistry 1.0.0
mcp-registry: io.github.donniertf-hub/jp-business-calendar-mcp@1.0.0Source repositoryProject website
Maintenance checked

Protocol and capabilities

Server
jp-business-calendar-mcp 1.0.0
MCP protocol
2025-06-18
Tools
4 advertised
Resources
Not advertised
Resource templates
Not advertised
Prompts
Not advertised
Server-advertised capabilities
{
  "tools": {
    "listChanged": false
  }
}

Server-provided instructions

Untrusted server output shown for inspection. It is not Koskamo guidance and is excluded from knowledge search.

Japan Business Calendar. next_holidays is free. Subscribe (¥1200/month, cancel anytime) at https://jp-business-calendar-mcp.donniertf.workers.dev/buy for the paid tools, then pass access_token.

Tools

4 advertised

next_holidays
Advertised by the server during the last successful anonymous check.

FREE. Next 3 Japanese public holidays and whether today is a business day.

next_holidays input schema
{
  "type": "object",
  "properties": {}
}
business_days
Advertised by the server during the last successful anonymous check.

PRO. Add/subtract N Japanese business days from a date.

business_days input schema
{
  "type": "object",
  "required": [
    "start",
    "days"
  ],
  "properties": {
    "days": {
      "type": "number"
    },
    "start": {
      "type": "string"
    },
    "access_token": {
      "type": "string",
      "description": "Subscriber token from /success (or Authorization: Bearer)"
    }
  }
}
due_date
Advertised by the server during the last successful anonymous check.

PRO. Invoice due date: start + N calendar or business days.

due_date input schema
{
  "type": "object",
  "required": [
    "start",
    "days"
  ],
  "properties": {
    "days": {
      "type": "number"
    },
    "mode": {
      "type": "string"
    },
    "start": {
      "type": "string"
    },
    "access_token": {
      "type": "string",
      "description": "Subscriber token from /success (or Authorization: Bearer)"
    }
  }
}
year_planner
Advertised by the server during the last successful anonymous check.

PRO. Full holiday list from the dataset.

year_planner input schema
{
  "type": "object",
  "properties": {
    "access_token": {
      "type": "string",
      "description": "Subscriber token from /success (or Authorization: Bearer)"
    }
  }
}

Prompts

Not advertised

No prompt definitions available.

Resources

Not advertised

No resource definitions available.

30-day availability

Aggregated from read-only remote checks; this is not a tool-execution or security guarantee.

Successful checks
1 of 1 (100%)
Average latency
523 ms
95th percentile latency
523 ms

Maintenance history

Public check and source-refresh events. Editorial and ownership records remain private.

  • · probe · passed · 523 ms · metadata changed · 4 tool(s)

Connect from your client

Each snippet registers the same endpoint; pick the client you use.

This server is operated by the named third party. Listing and endpoint checks are not an endorsement or a security audit. Review the operator's permissions, terms, and data handling before connecting. How listings are checked and corrected.

Claude Code

Run this once in a terminal. It registers the remote server. Use --scope project to write .mcp.json for the repo.
Claude Code configuration
claude mcp add --transport http japan-business-calendar-mcp https://jp-business-calendar-mcp.donniertf.workers.dev/mcp

Codex

Run this once. Codex stores MCP servers in ~/.codex/config.toml (or .codex/config.toml in a trusted project).
Codex configuration
codex mcp add japan-business-calendar-mcp --url https://jp-business-calendar-mcp.donniertf.workers.dev/mcp

Cursor

Merge this server into .cursor/mcp.json in your project, then enable japan-business-calendar-mcp in your MCP settings.
Cursor configuration
{
  "mcpServers": {
    "japan-business-calendar-mcp": {
      "url": "https://jp-business-calendar-mcp.donniertf.workers.dev/mcp"
    }
  }
}

Cline

Merge this into cline_mcp_settings.json (Cline → MCP Servers → Configure).
Cline configuration
{
  "mcpServers": {
    "japan-business-calendar-mcp": {
      "type": "streamableHttp",
      "url": "https://jp-business-calendar-mcp.donniertf.workers.dev/mcp",
      "disabled": false
    }
  }
}

VS Code

Merge this server into .vscode/mcp.json. Use MCP: List Servers to start japan-business-calendar-mcp and inspect its tools.
VS Code configuration
{
  "servers": {
    "japan-business-calendar-mcp": {
      "type": "http",
      "url": "https://jp-business-calendar-mcp.donniertf.workers.dev/mcp"
    }
  }
}

Gemini CLI

Run this once. It writes .gemini/settings.json in the current project; pass --scope user for ~/.gemini/settings.json.
Gemini CLI configuration
gemini mcp add --transport http japan-business-calendar-mcp https://jp-business-calendar-mcp.donniertf.workers.dev/mcp

Claude Desktop

Merge this into claude_desktop_config.json (macOS: ~/Library/Application Support/Claude/, Windows: %APPDATA%\Claude\), then restart Claude Desktop.
Claude Desktop configuration
{
  "mcpServers": {
    "japan-business-calendar-mcp": {
      "url": "https://jp-business-calendar-mcp.donniertf.workers.dev/mcp"
    }
  }
}

Windsurf

Merge this into ~/.codeium/windsurf/mcp_config.json, then refresh MCP in Cascade. Windsurf remote servers use serverUrl, not url.
Windsurf configuration
{
  "mcpServers": {
    "japan-business-calendar-mcp": {
      "serverUrl": "https://jp-business-calendar-mcp.donniertf.workers.dev/mcp"
    }
  }
}

Let your agent find its tools

Find servers like Japan Business Calendar MCP from your agent. Add Koskamo once to search the index for endpoints, access requirements, and client setup. Public discovery needs no key.

Connect Koskamo Explore workflows
See all 4,475