# PlugRail Japanese Calendar Muse connector

From musedirectory.ai, the independent directory of Meta Muse connectors. Not affiliated with Meta.

## PlugRail Japanese Calendar

Check Japanese holidays and calculate business days for payroll, invoicing and scheduling.

- Record: https://musedirectory.ai/connector/plugrail-japanese-calendar
- Category: Productivity
- Developer: PlugRail (https://plugrail.dev)
- Muse status: Extra setup. Not in Muse's Connectors list yet. Muse can still use it: its page gives you a request to paste into Muse.
- Health: Working, 993ms, checked 2026-09-28T08:45:52Z
- Endpoint: https://jp-calendar.plugrail.dev/mcp
- Auth: No account needed; Pricing: unknown
- Screening: Screened, no issues found (2026-09-24T23:00:44Z)
- Source: Found in the official MCP Registry (dev.plugrail/jp-calendar) https://registry.modelcontextprotocol.io/v0/servers?search=dev.plugrail%2Fjp-calendar

Calculates Japanese holidays and business days using official Japan Cabinet Office data. Helps with payroll deadlines, invoice due dates, and scheduling by excluding weekends, national holidays, and optional banking closures.

Example request: "How many business days until my invoice is due on July 20th, excluding weekends and Japanese holidays?"

How to connect: Not in Muse's Connectors list yet, but Muse can still use it. Paste this into Muse: "Use PlugRail Japanese Calendar to help me. It is a free service with an MCP server at https://jp-calendar.plugrail.dev/mcp. It does not need an API key. Ask me before you share anything with it." Muse asks before it shares anything with the app's site. Meta does not review apps used this way, so only use ones you trust. We tested this in the Muse app on September 24, 2026: Muse used an app's link directly this way and returned a live answer.

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,

Screening checks:
- MCP handshake: pass (Answered in 1192ms)
- Domain against threat feeds (Cloudflare security DNS): pass (jp-calendar.plugrail.dev, plugrail.dev not flagged)
- Published packages against the OSV malicious-package database: n/a (No npm or PyPI package published)
- Hidden instructions or invisible characters in tool text: pass (4 tools read, nothing found)
- Inputs asking for passwords, card numbers or seed phrases: pass (None found)
- Domain and redirects: pass (Domain registered 76 days ago)
- AI review of purpose and tool behavior: pass (No concerns)