Date Calculator

Date Calculator

An MCP server for date calculations and public holidays, using the same date calculator created by Online Alarm Kur.

This repository contains documentation and registration metadata for the hosted service.

• Endpoint: https://mcp.onlinealarmkur.com/
• Transport: Streamable HTTP
• Authentication: None
• Documentation: mcp.onlinealarmkur.com

Tools

Tool	What it does
count_days	Count days between two dates: a plain difference, or business days with selected weekdays and public holidays excluded. Plain counts also give elapsed years, months and days.
shift_date	Add or subtract years, months, weeks and days, with optional weekday and holiday exclusions. roll can move a plain date to the next or previous working day.
get_holidays	List public holidays with their weekdays, including observed dates, for a country and optional region, for up to 11 years per request.
list_locations	Without a country, get a compact list of supported countries and available years. With a country, get its exact region codes.

Dates use the Gregorian calendar in YYYY-MM-DD format, without a time of day. Weekends and holidays are included unless explicitly excluded. Some countries have a different weekend, so choose the weekdays for the country. Holidays count as full days; the data does not mark half-day holidays.

Without region, holiday calculations use the national calendar only, and the result includes a warning if the country has regions.

Date calculation results include the weekday and ISO week of each date, any warnings, the rules used and a share link that opens the calculation on the website. A result that uses roll has a link to the plain calculation, because the website has no roll setting. Calculation and holiday tools accept the website's 32 languages; holiday names may fall back to their native language.

Connect

Claude

1. Open Customize, then Connectors.
2. Select + Add, then Add custom connector.
3. Enter Date Calculator as the name and https://mcp.onlinealarmkur.com/ as the URL, then select Continue.
4. Under Authentication, choose No sign in, then select Add.

On Team and Enterprise plans, an organization owner adds the connector first; members then connect it. See Anthropic's custom connector instructions.

Claude Code

claude mcp add --transport http date-calculator https://mcp.onlinealarmkur.com/

Cursor

Add this entry to ~/.cursor/mcp.json:

{
  "mcpServers": {
    "date-calculator": {
      "url": "https://mcp.onlinealarmkur.com/"
    }
  }
}

VS Code

Add this entry to .vscode/mcp.json:

{
  "servers": {
    "date-calculator": {
      "type": "http",
      "url": "https://mcp.onlinealarmkur.com/"
    }
  }
}

If the configuration file already contains other servers, add the entry to the existing object.

ChatGPT

Where your account and workspace allow custom MCP connections:

1. Open ChatGPT Plugins in your browser.
2. Select the plus button, then Add custom MCP server.
3. Enter Date Calculator as the name and https://mcp.onlinealarmkur.com/ as the server URL. Choose no authentication.
4. Review the permissions and warning, then select Create as a plugin.
5. Install the resulting plugin, start a new conversation and select it using @.

See OpenAI's custom MCP server instructions.

Grok

1. Open Grok Connectors.
2. Select New Connector, then Custom.
3. Enter https://mcp.onlinealarmkur.com/ as the MCP server URL. No authentication is required by this server.
4. Complete the setup to make the tools available in conversations.

For Grok Business and Enterprise, a team admin must first add the connector for the organization.

See Grok's connector documentation.

Other MCP clients

Where custom remote MCP connections are available, use https://mcp.onlinealarmkur.com/ with Streamable HTTP and no authentication. See the connection instructions.

Example prompts

• "How many working days are there between 2 November and 24 December 2026 in Germany, excluding Saturdays, Sundays and public holidays?"
• "What date is 90 days after 15 January 2027?"
• "List the public holidays in Turkey for 2027."

Limits

Rate limits apply. Holiday lookups share a daily budget; if it is exhausted, holiday features pause until 00:00 UTC. Calculations without holidays remain available.

Future holiday dates can change. Check important deadlines with the relevant authority.

Support

For bug reports and questions, open an issue. Report security problems privately with Report a vulnerability.

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