Timezone Toolkit

Available Tools

Tool	Description
convert_time	Convert a time from one timezone to another
get_current_time	Get the current time in a specified timezone
calculate_sunrise_sunset	Calculate sunrise, sunset, and twilight times for a specific location and date
calculate_moon_phase	Calculate moon phase for a specific date
calculate_timezone_difference	Calculate the time difference between two timezones
list_timezones	List available IANA timezones, optionally filtered by region
calculate_countdown	Calculate time remaining until a specific date/event
calculate_business_days	Calculate business days between two dates (excluding weekends)
format_date	Format a date in various styles

🌟 Features

🕒 Basic Timezone Conversion

• Convert times between any IANA timezone
• Get current time in any timezone
• Format time in various styles (short, medium, full)
• Calculate time differences in hours/minutes
• List available IANA timezones

🌅 Sunrise/Sunset and Astronomical Calculations

• Calculate sunrise and sunset times for any location
• Include twilight times (civil, nautical, astronomical)
• Calculate day length for any location/date
• Calculate moon phases for any date

📅 Date and Time Utilities

• Format dates in various styles (short, medium, full, ISO, relative)
• Calculate business days between dates
• Create countdown timers to future events
• Support for multiple locales and timezones

💻 Installation

Prerequisites

• Node.js 18.x or higher - The TimezoneToolkit MCP server requires Node.js 18+ to run properly.

Setup

To run the TimezoneToolkit MCP server using Node.js npx, use the following command:

npx -y @cicatriz/timezone-toolkit@latest

Client-Specific Installation

Cursor

To add this server to Cursor IDE:

1. Go to Cursor Settings > MCP
2. Click + Add new Global MCP Server
3. Add the following configuration to your global .cursor/mcp.json file:

{
  "mcpServers": {
    "timezone-toolkit": {
      "command": "npx",
      "args": [
        "-y",
        "@cicatriz/timezone-toolkit"
      ]
    }
  }
}

See the Cursor documentation for more details.

Windsurf

To set up MCP with Cascade, navigate to Windsurf - Settings > Advanced Settings or Command Palette > Open Windsurf Settings Page.

Scroll down to the Cascade section and add the TimezoneToolkit MCP server directly in mcp_config.json:

{
  "mcpServers": {
    "timezone-toolkit": {
      "command": "npx",
      "args": [
        "-y",
        "@cicatriz/timezone-toolkit"
      ]
    }
  }
}

Cline

Add the following JSON manually to your cline_mcp_settings.json via Cline MCP Server setting:

{
  "mcpServers": {
    "timezone-toolkit": {
      "command": "npx",
      "args": [
        "-y",
        "@cicatriz/timezone-toolkit"
      ]
    }
  }
}

Roo Code

Access the MCP settings by clicking Edit MCP Settings in Roo Code settings or using the Roo Code: Open MCP Config command in VS Code's command palette:

{
  "mcpServers": {
    "timezone-toolkit": {
      "command": "npx",
      "args": [
        "-y",
        "@cicatriz/timezone-toolkit"
      ]
    }
  }
}

Claude

Add the following to your claude_desktop_config.json file:

{
  "mcpServers": {
    "timezone-toolkit": {
      "command": "npx",
      "args": [
        "-y",
        "@cicatriz/timezone-toolkit"
      ]
    }
  }
}

See the Claude Desktop documentation for more details.

CLI

You can also run it as CLI by running the following command:

npx -y @cicatriz/timezone-toolkit@latest

Alternative Installation Methods

Install from npm

# Install globally from npm
npm install -g @cicatriz/timezone-toolkit

# Run the server
timezone-toolkit

Manual Installation

# Clone the repository
git clone https://github.com/Cicatriiz/timezone-toolkit.git
cd timezone-toolkit

# Install dependencies
npm install

# Build the project
npm run build

# Run the server
node dist/index.js

💬 Usage with Claude Desktop

After installation, you can use TimezoneToolkit with Claude Desktop:

1. Open Claude Desktop
2. Start a new conversation
3. Click the hammer icon to see available tools
4. Select any of the TimezoneToolkit tools

🔗 API Access

TimezoneToolkit also provides a RESTful API for accessing its functionality without Claude Desktop:

Starting the API Server

# Using npm
npm install -g @cicatriz/timezone-toolkit
node server.js

The API server will be available at http://localhost:3000

API Endpoints

• GET /api/tools - List all available tools
• POST /api/convert-time - Convert time between timezones
• POST /api/current-time - Get current time in a timezone
• POST /api/sunrise-sunset - Calculate sunrise/sunset times
• POST /api/moon-phase - Calculate moon phase
• POST /api/timezone-difference - Calculate timezone difference
• POST /api/list-timezones - List available timezones
• POST /api/countdown - Calculate countdown to a date
• POST /api/business-days - Calculate business days between dates
• POST /api/format-date - Format a date

For detailed API documentation, see the API README.

Example Queries

• "What time is it now in Tokyo?"
• "Convert 3:00 PM New York time to London time"
• "What time is sunrise tomorrow in San Francisco?"
• "When is sunset today in Paris?"
• "What's the current moon phase?"
• "What's the time difference between New York and Tokyo?"
• "Show me a list of European timezones"
• "How many business days are there between March 1 and April 15?"
• "Format today's date in French locale"
• "How much time is left until New Year's Eve?"

🔧 Available Tools

1. convert_time

Converts a time from one timezone to another.

Parameters:

• time (optional): Time to convert (ISO string or natural language). Defaults to current time if not provided.
• fromTimezone: Source IANA timezone name (e.g., 'America/New_York')
• toTimezone: Target IANA timezone name (e.g., 'Europe/London')
• format (optional): Output format ('short', 'medium', 'full'). Defaults to 'medium'

Example:

{
  "time": "2023-12-25T14:30:00",
  "fromTimezone": "America/New_York",
  "toTimezone": "Asia/Tokyo",
  "format": "full"
}

Response:

{
  "originalTime": "2023-12-25T14:30:00.000-05:00",
  "convertedTime": "Tuesday, December 26, 2023, 4:30:00 AM Japan Standard Time",
  "fromTimezone": "America/New_York",
  "toTimezone": "Asia/Tokyo",
  "timeDifference": "+14 hours"
}

2. get_current_time

Gets the current time in a specified timezone.

Parameters:

• timezone: IANA timezone name (e.g., 'Asia/Tokyo')
• format (optional): Output format ('short', 'medium', 'full'). Defaults to 'medium'

Example:

{
  "timezone": "Europe/London",
  "format": "full"
}

Response:

{
  "currentTime": "Monday, March 25, 2025, 10:15:30 PM British Summer Time",
  "timezone": "Europe/London",
  "utcOffset": "+01:00"
}

3. calculate_sunrise_sunset

Calculates sunrise, sunset, and twilight times for a specific location and date.

Parameters:

• date (optional): Date for calculation (ISO string or natural language). Defaults to current date.
• latitude: Latitude of the location (-90 to 90)
• longitude: Longitude of the location (-180 to 180)
• timezone (optional): IANA timezone name (e.g., 'Europe/Paris'). Defaults to UTC.

Example:

{
  "date": "2023-06-21",
  "latitude": 37.7749,
  "longitude": -122.4194,
  "timezone": "America/Los_Angeles"
}

Response:

{
  "date": "2023-06-21",
  "sunrise": "05:48:11 AM",
  "sunset": "08:35:13 PM",
  "civilTwilight": {
    "dawn": "05:17:22 AM",
    "dusk": "09:06:02 PM"
  },
  "nauticalTwilight": {
    "dawn": "04:38:43 AM",
    "dusk": "09:44:41 PM"
  },
  "astronomicalTwilight": {
    "dawn": "03:52:50 AM",
    "dusk": "10:30:34 PM"
  },
  "dayLength": "14 hours 47 minutes",
  "timezone": "America/Los_Angeles"
}

4. calculate_moon_phase

Calculates moon phase for a specific date.

Parameters:

• date (optional): Date for calculation (ISO string or natural language). Defaults to current date.
• timezone (optional): IANA timezone name (e.g., 'Europe/Paris'). Defaults to UTC.

Example:

{
  "date": "2023-01-06",
  "timezone": "UTC"
}

Response:

{
  "date": "2023-01-06",
  "phase": 0.998,
  "phaseName": "Full Moon",
  "illumination": 0.997,
  "timezone": "UTC"
}

5. calculate_timezone_difference

Calculates the time difference between two timezones.

Parameters:

• fromTimezone: Source IANA timezone name (e.g., 'America/New_York')
• toTimezone: Target IANA timezone name (e.g., 'Europe/London')

Example:

{
  "fromTimezone": "America/New_York",
  "toTimezone": "Asia/Tokyo"
}

Response:

{
  "fromTimezone": "America/New_York",
  "toTimezone": "Asia/Tokyo",
  "timeDifference": "+14 hours",
  "currentTimeFrom": "3/25/2025, 6:15 PM",
  "currentTimeTo": "3/26/2025, 8:15 AM",
  "hoursDifference": 14,
  "minutesDifference": 0,
  "totalMinutesDifference": 840,
  "direction": "ahead"
}

6. list_timezones

Lists available IANA timezones, optionally filtered by region.

Parameters:

• region (optional): Filter timezones by region (e.g., 'America', 'Europe', 'Asia')

Example:

{
  "region": "Europe"
}

Response:

{
  "timezones": [
    {
      "timezone": "Europe/Amsterdam",
      "currentTime": "3/25/2025, 11:15 PM",
      "offset": "+02:00"
    },
    {
      "timezone": "Europe/Berlin",
      "currentTime": "3/25/2025, 11:15 PM",
      "offset": "+02:00"
    },
    // Additional European timezones...
  ],
  "count": 7,
  "region": "Europe"
}

7. calculate_countdown

Calculates time remaining until a specific date/event.

Parameters:

• targetDate: Target date/time (ISO string or natural language)
• timezone (optional): IANA timezone name (e.g., 'America/New_York'). Defaults to system timezone.
• title (optional): Title or name of the event

Example:

{
  "targetDate": "2025-12-31T23:59:59",
  "timezone": "UTC",
  "title": "New Year's Eve"
}

Response:

{
  "title": "New Year's Eve",
  "targetDate": "2025-12-31T23:59:59.000Z",
  "formattedTargetDate": "Wednesday, December 31, 2025, 11:59:59 PM GMT",
  "currentDate": "2025-03-25T18:15:30.000Z",
  "timezone": "UTC",
  "isPast": false,
  "countdown": "9 months, 6 days, 5 hours, 44 minutes, 29 seconds",
  "remaining": {
    "years": 0,
    "months": 9,
    "days": 6,
    "hours": 5,
    "minutes": 44,
    "seconds": 29,
    "totalDays": 281,
    "totalHours": 6749,
    "totalMinutes": 404969,
    "totalSeconds": 24298169
  }
}

8. calculate_business_days

Calculates business days between two dates (excluding weekends).

Parameters:

• startDate: Start date (ISO string or natural language)
• endDate: End date (ISO string or natural language)
• timezone (optional): IANA timezone name (e.g., 'America/New_York'). Defaults to system timezone.
• excludeHolidays (optional): Whether to exclude common holidays (US holidays only). Defaults to false.

Example:

{
  "startDate": "2023-05-01",
  "endDate": "2023-05-31",
  "timezone": "UTC",
  "excludeHolidays": true
}

Response:

{
  "startDate": "2023-05-01",
  "endDate": "2023-05-31",
  "businessDays": 22,
  "calendarDays": 31,
  "weekendDays": 8,
  "holidaysExcluded": 1,
  "timezone": "UTC",
  "businessDatesIncluded": ["2023-05-01", "2023-05-02", "2023-05-03", "2023-05-04", "2023-05-05", "2023-05-08", "2023-05-09", "2023-05-10", "2023-05-11", "2023-05-12", "2023-05-15", "2023-05-16", "2023-05-17", "2023-05-18", "2023-05-19", "2023-05-22", "2023-05-23", "2023-05-24", "2023-05-25", "2023-05-26", "2023-05-30", "2023-05-31"]
}

9. format_date

Formats a date in various styles.

Parameters:

• date: Date to format (ISO string or natural language). Defaults to current date.
• timezone (optional): IANA timezone name (e.g., 'America/New_York'). Defaults to system timezone.
• format (optional): Output format ('short', 'medium', 'full', 'iso', 'relative'). Defaults to 'medium'.
• locale (optional): Locale for formatting (e.g., 'en-US', 'fr', 'de'). Defaults to 'en-US'.

Example:

{
  "date": "2023-12-25",
  "timezone": "Europe/Paris",
  "format": "full",
  "locale": "fr"
}

Response:

{
  "originalDate": "2023-12-25",
  "parsedDate": "2023-12-25T00:00:00.000+01:00",
  "formattedDate": "lundi 25 décembre 2023",
  "formattedTime": "00:00:00 heure normale d'Europe centrale",
  "formattedDateTime": "lundi 25 décembre 2023 à 00:00:00 heure normale d'Europe centrale",
  "dayOfWeek": "lundi",
  "dayOfMonth": 25,
  "month": "décembre",
  "year": 2023,
  "timezone": "Europe/Paris",
  "locale": "fr",
  "format": "full"
}

💬 Example Queries in Claude Desktop

• "What time is it now in Tokyo?"
• "Convert 3:00 PM New York time to London time"
• "What time is sunrise tomorrow in San Francisco?"
• "When is sunset today in Paris?"
• "What's the current moon phase?"
• "What's the time difference between New York and Tokyo?"
• "Show me a list of European timezones"
• "How many business days are there between March 1 and April 15?"
• "Format today's date in French locale"
• "How much time is left until New Year's Eve?"

💻 Technical Details

Architecture

TimezoneToolkit is built using the Model Context Protocol (MCP) specification, which allows it to integrate seamlessly with Claude Desktop. The server is implemented in TypeScript and uses the following architecture:

• Core Services: Implements timezone conversion, astronomical calculations, and date formatting
• MCP Server: Handles JSON-RPC requests from Claude Desktop
• Utility Functions: Provides helper functions for date/time operations
• Testing Framework: Includes a comprehensive test script for verifying functionality

Dependencies

• Luxon - For all date/time handling and timezone operations
• SunCalc - For sunrise/sunset and astronomical calculations
• @modelcontextprotocol/sdk - For MCP server implementation

Requirements

• Node.js 18.x or higher
• npm 9.x or higher
• Claude Desktop (latest version)

📝 Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add some amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

🧪 Testing

TimezoneToolkit includes a comprehensive test script that can be used to verify the functionality of the MCP server. The test script can be used to test the local build, the version flag, list all available tools, test specific tools, and test the npm package after publishing.

Running Tests

# Test the local build (default)
node test-server.js

# Test a specific tool
node test-server.js --tool=calculate_sunrise_sunset

# List all available tools
node test-server.js --list

# Test the version flag
node test-server.js --test-version

# Test the published npm package (after publishing)
node test-server.js --npm

The test script will output detailed information about the test results, including whether the response format is correct and whether the content is valid JSON.

Example Output

Testing local build...
Running: node /path/to/timezone-toolkit/dist/index.js

Sending request: {
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "get_current_time",
    "arguments": {
      "timezone": "America/New_York"
    }
  }
}

Response: {
  "result": {
    "content": [
      {
        "type": "text",
        "text": "{\n  \"currentTime\": \"Mar 25, 2025, 9:54 PM\",\n  \"timezone\": \"America/New_York\",\n  \"utcOffset\": \"-04:00\"\n}"
      }
    ]
  },
  "jsonrpc": "2.0",
  "id": 1
}
✅ Response format is correct (has content array)
✅ Content is valid JSON: {
  currentTime: 'Mar 25, 2025, 9:54 PM',
  timezone: 'America/New_York',
  utcOffset: '-04:00'
}

✅ Test completed successfully!

🐛 Troubleshooting

Common Issues

1. Tool not showing up in Claude Desktop

   • Make sure the server is properly configured in Claude Desktop settings
   • Check that the path to the index.js file is correct
   • Restart Claude Desktop

2. Incorrect timezone calculations

   • Verify that you're using valid IANA timezone names (e.g., 'America/New_York', not 'EST')
   • Check for daylight saving time transitions which can affect calculations

3. Sunrise/sunset calculations not working

   • Ensure latitude and longitude values are valid (-90 to 90 for latitude, -180 to 180 for longitude)
   • Some extreme northern/southern locations may have periods with no sunrise/sunset

🔒 Privacy & Security

TimezoneToolkit processes all data locally and does not send any information to external servers. Your timezone data and queries remain private on your device.

📃 License

ISC

👨‍💻 Author

Cicatriz