MCP DateTime

Instructions

Implementation Reference

• src/server.ts:19-28 (registration)

  Registration of the 'get-current-time' tool with an inline asynchronous handler function that retrieves the current timezone and formats the current time in that timezone using helper functions.

  server.tool(
    "get-current-time",
    "Get the current time in the configured local timezone",
    async () => ({
      content: [{ 
        type: "text", 
        text: `The current time is ${getCurrentTimeInTimezone(getCurrentTimezone())}`
      }]
    })
  );

• src/timezone-utils.ts:66-74 (helper)

  Helper function that returns the current system timezone by querying Intl.DateTimeFormat, with fallback to 'UTC' on error. Called by the get-current-time handler.

  export function getCurrentTimezone(): string {
    try {
      const timezone = Intl.DateTimeFormat().resolvedOptions().timeZone;
      return processTimezone(timezone);
    } catch (error) {
      console.error("Error getting current timezone:", error);
      return "UTC"; // Default to UTC if there's an error
    }
  }

• src/timezone-utils.ts:96-147 (helper)

  Helper function that formats the current date and time in ISO8601 format for the specified timezone using Intl APIs. Called by the get-current-time handler.

  export function getCurrentTimeInTimezone(timezone: string): string {
    try {
      const date = new Date();
      
      // Create a formatter that includes the timezone
      const options: Intl.DateTimeFormatOptions = {
        timeZone: timezone,
        timeZoneName: 'short'
      };
      
      // Get the timezone offset from the formatter
      const formatter = new Intl.DateTimeFormat('en-US', options);
      const formattedDate = formatter.format(date);
      const timezonePart = formattedDate.split(' ').pop() || '';
      
      // Format the date in ISO8601 format with the timezone
      // First get the date in the specified timezone
      const tzFormatter = new Intl.DateTimeFormat('en-US', {
        timeZone: timezone,
        year: 'numeric',
        month: '2-digit',
        day: '2-digit',
        hour: '2-digit',
        minute: '2-digit',
        second: '2-digit',
        hour12: false,
        fractionalSecondDigits: 3
      });
      
      const parts = tzFormatter.formatToParts(date);
      const dateParts: Record<string, string> = {};
      
      parts.forEach(part => {
        if (part.type !== 'literal') {
          dateParts[part.type] = part.value;
        }
      });
      
      // Format as YYYY-MM-DDTHH:MM:SS.sss±HH:MM (ISO8601)
      const isoDate = `${dateParts.year}-${dateParts.month}-${dateParts.day}T${dateParts.hour}:${dateParts.minute}:${dateParts.second}.${dateParts.fractionalSecond || '000'}`;
      
      // For proper ISO8601, we need to add the timezone offset
      // We can use the Intl.DateTimeFormat to get the timezone offset
      const tzOffset = new Date().toLocaleString('en-US', { timeZone: timezone, timeZoneName: 'longOffset' }).split(' ').pop() || '';
      
      // Format the final ISO8601 string
      return `${isoDate}${tzOffset.replace('GMT', '')}`;
    } catch (error) {
      console.error(`Error formatting time for timezone ${timezone}:`, error);
      return 'Invalid timezone';
    }
  }