Worldclock MCP Server

World Clock Pro MCP server

Give your AI agent a real clock. Public, read-only, no API key:

https://worldclock.pro/mcp

Models cannot reliably compute local times, DST transitions, or timezone math on their own. This server gives any MCP-capable assistant live answers from the IANA timezone database and a 224,000+ city registry, with the answer's source page cited in every response.

• Live endpoint: https://worldclock.pro/mcp (Streamable HTTP, stateless, JSON-RPC 2.0)
• How-to page: worldclock.pro/mcp
• Server card: /.well-known/mcp/server-card.json
• Registry name: pro.worldclock/time (domain-verified)

Quick connect

Claude Code

claude mcp add --transport http worldclockpro-time https://worldclock.pro/mcp

Claude Desktop — Settings → Connectors → Add custom connector → paste the URL.

Cursor — paste into ~/.cursor/mcp.json (or use the button on worldclock.pro/mcp):

{ "mcpServers": { "worldclockpro-time": { "url": "https://worldclock.pro/mcp" } } }

VS Code

code --add-mcp '{"name":"worldclockpro-time","type":"http","url":"https://worldclock.pro/mcp"}'

ChatGPT — Settings → Apps & Connectors → Advanced settings → enable Developer mode → create a connector with the URL and No authentication. The server is read-only, so it works on plans where custom connectors are limited to read-only tools.

OpenClaw — add to openclaw.json:

{ "mcp": { "servers": { "worldclockpro-time": { "url": "https://worldclock.pro/mcp", "transport": "streamable-http" } } } }

MCP Inspector

npx @modelcontextprotocol/inspector
# Transport: "Streamable HTTP" → URL: https://worldclock.pro/mcp

Tools

Every result includes a source_url linking the matching worldclock.pro page, so answers can cite a live source.

Ways to describe a place

• City name or alias — "Tokyo", "new-york", "nyc", "Москва", "São Paulo"
• Timezone — IANA id ("America/New_York") or abbreviation ("PST", "ET", "UTC")
• Coordinates — latitude + longitude; the answer names the nearest city

Use as a Claude Code plugin

This repo is itself a plugin marketplace:

/plugin marketplace add worldclockpro/worldclock-mcp
/plugin install world-clock@worldclockpro

The plugin wires up the remote MCP server and installs the world-clock skill, which teaches the assistant when to use which tool and the classic timezone traps (EST vs ET, half-hour offsets, date-line weekday changes).

Use as an OpenClaw skill

The same skill follows the Agent Skills format:

npx clawhub@latest install world-clock   # once published on ClawHub
# or copy skills/world-clock/ into your skills directory

Why trust it

• Read-only by design. Every tool declares readOnlyHint: true. There are no write operations, no accounts, and nothing to sign in for.
• No tracking. Queries are computed in memory and not stored. See the privacy policy.
• Live IANA data. DST rules come from the IANA timezone database, updated with the weekly data refresh, never hard-coded.
• Run by an established team. The people behind the World Clock Master (Apple Editor's Choice) and World Clock Pro apps.
• Domain-verified. The registry listing pro.worldclock/time is published with cryptographic proof of control of worldclock.pro.

Limits and errors

• Up to 50 locations per call (search_cities returns up to 25 matches).
• Per-IP rate limit: 60 calls per 10 seconds (HTTP 429 with Retry-After beyond that).
• Invalid input returns structured errors (LOCATION_NOT_FOUND, INVALID_TIMEZONE, AMBIGUOUS_INSTANT, ...) an agent can read and recover from.

Links

• Website: worldclock.pro
• Agent guide: worldclock.pro/llms.txt
• Support: support@worldclock.pro

MIT licensed. See SECURITY.md for the security posture.