PlugRail Japanese Calendar

Name: PlugRail Japanese Calendar
Author: plugrail

@plugrailMCP server · External

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

Government open datav0.2.0MITTypeScript

Freeno charge per call

One address for any MCP client. No sign-in needed on this server.

What it does

1 read1 act2 other

Grouped by tool name. At most: only reads or looks up information.

What it costs

Free

Odel charges nothing per call. The publisher may charge for its own service.

Tools

4 · grouped by tool name · checked 12 Oct 2026

Read · 1Look things up

list_holidays

Act · 1Change something

add_business_days

Other · 2Neither hinted nor named

is_holiday
business_days_between

Try it in the Inspector

README1 min readView on GitHub

plugrail

A collection of MCP servers that connect to Japanese public data. The name alone does not describe the project, so plugrail is not related to railways or railway services.

Live servers

Server	MCP endpoint	Tools	Status
jp-calendar	`https://jp-calendar.plugrail.dev/mcp`	`is_holiday`, `list_holidays`, `business_days_between`, `add_business_days`	Live

Connect

See the jp-calendar connection guide.

Self-hosting

In packages/servers/jp-calendar/, copy wrangler.example.jsonc to wrangler.jsonc and fill in your Cloudflare resource IDs.
Create the D1 database and KV namespace referenced by that configuration.
Run pnpm --filter @plugrail/jp-calendar deploy.

The self-hosted server runs independently. Authentication, rate limiting, and usage metering are features of the hosted service only.

Architecture

text

MCP client
    |
    v
jp-calendar Worker --> Cloudflare D1 (holiday data)
                   --> Cloudflare KV (cached data)

Sources and disclaimer

This is not an official service of the National Tax Agency, the Digital Agency, or any other Japanese government body. Information provided does not represent their official views and is not guaranteed by them.

Source: Adapted from the Cabinet Office "National Holidays" page (https://www8.cao.go.jp/chosei/shukujitsu/gaiyou.html)