# PlugRail Japanese Calendar MCP server

Japanese holiday and business-day calculations using official Japan Cabinet Office data.

## At a glance

PlugRail Japanese Calendar is an MCP server in the Productivity category. It is hosted remotely and connects over HTTP, and declares no required credentials. It exposes 4 tools, including is_holiday, list_holidays and add_business_days. It scores B (73/100) on the MCP Skills Hub health score as of Oct 28, 2026.

## Install

### How to install PlugRail Japanese Calendar in Claude Code

1. Add the server

```bash
claude mcp add --transport http jp-calendar https://jp-calendar.plugrail.dev/mcp
```

2. Verify it's connected

```bash
claude mcp list
```

3. Sharing it with your team?

   Add `--scope project` to write it to .mcp.json in the repository root, which you can commit (with the secrets left as environment variables).

4. Use it in a session

   Ask Claude to use the tools this server exposes (e.g. is_holiday, list_holidays, add_business_days). It discovers them automatically.

### How to install PlugRail Japanese Calendar in Claude Desktop

1. Open your MCP config

   macOS: ~/Library/Application Support/Claude/claude_desktop_config.json · Windows: %APPDATA%\Claude\claude_desktop_config.json

2. Add this server

```json
{
  "mcpServers": {
    "jp-calendar": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote",
        "https://jp-calendar.plugrail.dev/mcp"
      ]
    }
  }
}
```

3. Why the wrapper?

   This is a remote (HTTP) server and Claude Desktop only launches local processes, so mcp-remote proxies the connection. It will open a browser window if the server needs OAuth.

4. Restart Claude Desktop

   The tools appear under the 🔌 menu once the app reloads.

### How to install PlugRail Japanese Calendar in Cursor

1. Create / edit .cursor/mcp.json in your project

```json
{
  "mcpServers": {
    "jp-calendar": {
      "url": "https://jp-calendar.plugrail.dev/mcp"
    }
  }
}
```

2. Enable it

   Cursor Settings → MCP → toggle the server on. Tools become available to the Composer/Agent.

### How to install PlugRail Japanese Calendar in Codex CLI

1. Add to ~/.codex/config.toml

```toml
[mcp_servers.jp-calendar]
command = "npx"
args = ["-y", "mcp-remote", "https://jp-calendar.plugrail.dev/mcp"]
```

2. Why the wrapper?

   Codex runs MCP servers as local processes, so mcp-remote bridges this HTTP endpoint to stdio.

3. Run Codex

   Codex loads MCP servers from config.toml on startup and exposes their tools to the agent.

### How to install PlugRail Japanese Calendar in Windsurf

1. Edit ~/.codeium/windsurf/mcp_config.json

```json
{
  "mcpServers": {
    "jp-calendar": {
      "serverUrl": "https://jp-calendar.plugrail.dev/mcp"
    }
  }
}
```

2. Reload

   Windsurf → Cascade → refresh MCP servers. Cascade can now call the tools.

### How to install PlugRail Japanese Calendar in Cline

1. Open Cline → MCP Servers → Configure

   Adds to cline_mcp_settings.json.

2. Add the server

```json
{
  "mcpServers": {
    "jp-calendar": {
      "type": "streamableHttp",
      "url": "https://jp-calendar.plugrail.dev/mcp"
    }
  }
}
```

### How to install PlugRail Japanese Calendar in VS Code

1. Create .vscode/mcp.json

```json
{
  "servers": {
    "jp-calendar": {
      "type": "http",
      "url": "https://jp-calendar.plugrail.dev/mcp"
    }
  }
}
```

2. Start it

   VS Code shows a ▶ Start action above the server entry. Agent mode (Copilot Chat) can then use the tools.

## Tools

- `is_holiday` — 指定した日付が日本の祝日（国民の祝日・休日）かどうかを判定します。内閣府公表データに基づきます。入力例: {"date": "2026-01-01"}
- `list_holidays` — 指定した年または期間の日本の祝日一覧を返します。入力例: {"year": 2026} または {"from": "2026-01-01", "to": "2026-06-30"}
- `add_business_days` — 指定した日付(date)の翌日から数えてN営業日目(days)の日付を返します。dateの当日は数えません。daysが負の場合は過去方向（dateの前日から遡ってN営業日目）に計算します。土日・日本の祝日を除外し、calendar="banking"を指定すると銀行休業日（12/31〜1/3）も除外します。dateが営業日かどうかだけ知りたい場合は is_holiday を使ってください（days=0でも同じ情報がskipped経由で得られます）。入力例: {"date": "2026-07-10", "days": 3}
- `business_days_between` — from〜to間の営業日数を数えます。既定では「fromを含まず、toを含む」境界です（例:「今日から支払期日まで何営業日か」）。include_from/include_toで境界を変更できます。土日・日本の祝日を除外し、calendar="banking"を指定すると銀行休業日（12/31〜1/3）も除外します。from > to の場合はエラーにせず、from/toとinclude_from/include_toを入れ替えて計算した結果の符号を反転した値（負の営業日数）を返します（反対称則: count(A,B,x,y) = -count(B,A,y,x)。A≠B、すなわちfrom≠toの場合に成立する恒等式で、from===toはこの分岐に入らないため対象外）。入力例: {"from": "2026-07-10", "to": "2026-07-20"}

Source repository: https://github.com/plugrail/servers

---

Source: https://mcp-skills-hub.vercel.app/mcps/dev-plugrail-jp-calendar · MCP Skills Hub · data as of 2026-10-28T12:31:05Z