# World Business Calendar (npm · @appmonster/mcp-world-calendar)

Public holidays and working-day math for 200+ countries and regions, local weekends. No keys.

- Trust score: 74/100 (medium)
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-10-24

## Components

- npm · `@appmonster/mcp-world-calendar`: 74/100 (this document), [markdown](https://verifymcp.io/servers/groove79-mcp-world-calendar/appmonster-mcp-world-calendar.md), [page](https://verifymcp.io/servers/groove79-mcp-world-calendar/appmonster-mcp-world-calendar)

## Channel facts

- Registry: `npm`
- Package: `@appmonster/mcp-world-calendar`
- Version: `0.1.0`
- Transport: `stdio`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-10-24.

- **Supply Chain Security**: 81/100
  - No malware found by supply-chain analysis.
  - CVE check failed: a known high-severity CVE affects zod 3.25.76, a direct dependency. A fixed version is available.
  - No install/post-install scripts declared.
  - 36 of 109 dependencies flagged as unhealthy.
- **Provenance & Transparency**: 100/100
  - Source repository is publicly reachable at the declared URL.
  - Cryptographically verified build provenance (signed, bound to groove79/kmcp).
  - Clear OSI-approved license (MIT).
  - Actively maintained (last published 0 days ago).
  - Publishes a security disclosure policy (SECURITY.md).
- **Schema Quality & AI Usability**: 68/100
  - AI-judged instruction clarity (good).
  - Context-footprint check failed: tool/resource definitions use about 680 tokens (~136/item across 5 items; 5 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 0/100
  - Stability not yet verified: not enough scan history yet (needs a 30-day window).
- **Tool Coverage**: 90/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 71% of tool parameters carry a description.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 5 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 5 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.

**Unverified: 1 category.** A category scored 0 because we could not verify it: a data source with nothing on this package, evidence we could not reach, or a check we could not run. We only credit what we can confirm.

## Install

### How do I install the World Business Calendar MCP server?

World Business Calendar runs locally as an npm package, launched with npx -y @appmonster/mcp-world-calendar. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add groove79-mcp-world-calendar -- npx -y @appmonster/mcp-world-calendar
```

### Cursor

```json
{
  "mcpServers": {
    "groove79-mcp-world-calendar": {
      "command": "npx",
      "args": [
        "-y",
        "@appmonster/mcp-world-calendar"
      ]
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "groove79-mcp-world-calendar": {
      "command": "npx",
      "args": [
        "-y",
        "@appmonster/mcp-world-calendar"
      ]
    }
  }
}
```

### Codex

```bash
codex mcp add groove79-mcp-world-calendar -- npx -y @appmonster/mcp-world-calendar
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "groove79-mcp-world-calendar": {
      "type": "local",
      "command": [
        "npx",
        "-y",
        "@appmonster/mcp-world-calendar"
      ],
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add groove79-mcp-world-calendar --command npx --arg -y --arg @appmonster/mcp-world-calendar
```

### Hermes

```yaml
mcp_servers:
  groove79-mcp-world-calendar:
    command: "npx"
    args: ["-y", "@appmonster/mcp-world-calendar"]
```

### Netclaw

```json
{
  "McpServers": {
    "groove79-mcp-world-calendar": {
      "Transport": "stdio",
      "Command": "npx",
      "Arguments": [
        "-y",
        "@appmonster/mcp-world-calendar"
      ]
    }
  }
}
```

### Vellum

```bash
assistant mcp add groove79-mcp-world-calendar -t stdio -c npx -a -y @appmonster/mcp-world-calendar
```

### Other

```json
{
  "mcpServers": {
    "groove79-mcp-world-calendar": {
      "command": "npx",
      "args": [
        "-y",
        "@appmonster/mcp-world-calendar"
      ]
    }
  }
}
```

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-10-24 (score 74, +15)

- [security improvement] Malware scan: unverified → pass

### 2026-10-23 (score 59)

First indexed and scored.

## MCP tools (5)

### `world_list_holidays` (~157 tokens)

List public holidays of a country (and optionally a state/region) for a year, with English and local names and substitute (observed) days. 200+ countries. Use for scheduling across countries, shipping cut-offs, payroll or market-closed days. Set types to include bank/optional/observance days.

Input parameters:

- `country` (string, required): ISO 3166-1 alpha-2 country code, e.g. US, GB, DE, JP, IN, AE
- `region` (string): Optional state/region code, e.g. CA (California) for US, BY (Bavaria) for DE. Regional holidays differ.
- `types` (array)
- `year` (integer, required)

### `world_is_business_day` (~180 tokens)

Tell whether a date is a working day in a country (not a weekend there, not a public holiday), and give the next and previous working days. Knows local weekends (Friday–Saturday in Saudi Arabia, Israel, Egypt…). Default date is today in that country.

Input parameters:

- `country` (string, required): ISO 3166-1 alpha-2 country code, e.g. US, GB, DE, JP, IN, AE
- `date` (string): yyyy-MM-dd
- `extraHolidays` (array): Company days off to treat as holidays
- `includeBank` (boolean): Also treat bank holidays as days off (default: public holidays only)
- `region` (string): Optional state/region code, e.g. CA (California) for US, BY (Bavaria) for DE. Regional holidays differ.

### `world_add_business_days` (~196 tokens)

Add or subtract N working days in a country (skipping its weekends and public holidays), or count working days between two dates. Use for delivery ETAs, contract or payment deadlines, SLA due dates. Needs country, from (default today there) and either days or to.

Input parameters:

- `country` (string, required): ISO 3166-1 alpha-2 country code, e.g. US, GB, DE, JP, IN, AE
- `days` (integer)
- `extraHolidays` (array): Company days off to treat as holidays
- `from` (string): yyyy-MM-dd
- `includeBank` (boolean): Also treat bank holidays as days off (default: public holidays only)
- `region` (string): Optional state/region code, e.g. CA (California) for US, BY (Bavaria) for DE. Regional holidays differ.
- `to`: yyyy-MM-dd

### `world_common_business_days` (~76 tokens)

Find dates that are working days in ALL of several countries (e.g. US, DE and JP teams), between two dates — for meetings, settlements or launches across borders. Max 10 countries, 92 days.

Input parameters:

- `countries` (array, required)
- `from` (string, required): yyyy-MM-dd
- `to` (required)

### `world_list_countries` (~71 tokens)

List supported country codes (200+) or, with country, its state/region codes for regional holidays.

Input parameters:

- `country` (string): ISO 3166-1 alpha-2 country code, e.g. US, GB, DE, JP, IN, AE
- `search` (string)

## Diagnostics

Captured diagnostic sections: Provenance, Vulnerabilities, Dependencies. The full working is on the page: https://verifymcp.io/servers/groove79-mcp-world-calendar/appmonster-mcp-world-calendar#diagnostics

## Score history

- 2026-10-24: 74
- 2026-10-23: 59

## Common questions

### What is the World Business Calendar MCP server?

World Business Calendar is an MCP server listed in the public MCP registry as io.github.groove79/mcp-world-calendar. Public holidays and working-day math for 200+ countries and regions, local weekends. No keys. This page covers its npm package (@appmonster/mcp-world-calendar).

### Is the World Business Calendar MCP server safe to use?

World Business Calendar scores 74 out of 100 on VerifyMCP. We recorded 1 known advisory against it as of 24 October 2026. It declares no install or post-install scripts. Its build provenance is signed and verified. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the World Business Calendar MCP server expose?

World Business Calendar exposes 5 tools: world_list_holidays, world_is_business_day, world_add_business_days, world_common_business_days, world_list_countries. Their descriptions and schemas cost roughly 680 tokens of context every time the server is loaded.

### Is the World Business Calendar MCP server still maintained?

World Business Calendar is still listed as active in the MCP registry. We last reached this channel on 24 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

### What licence is the World Business Calendar MCP server under?

World Business Calendar declares the MIT licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.

## Links

- npm package: https://www.npmjs.com/package/@appmonster/mcp-world-calendar
- Socket report: https://socket.dev/npm/package/@appmonster/mcp-world-calendar
- Repository: https://github.com/groove79/kmcp
- Website: https://okagent.kr/mcp
- Changelog RSS feed: https://verifymcp.io/servers/groove79-mcp-world-calendar/appmonster-mcp-world-calendar.xml
- Changelog JSON feed: https://verifymcp.io/servers/groove79-mcp-world-calendar/appmonster-mcp-world-calendar.json
- HTML version of this page: https://verifymcp.io/servers/groove79-mcp-world-calendar/appmonster-mcp-world-calendar