MCP DateTime

Instructions

Implementation Reference

• src/server.ts:73-84 (handler)

  The handler function for the 'list-timezones' tool, registered inline with server.tool(). It returns a text content with the formatted list of available timezones obtained from getFormattedTimezoneList().

  server.tool(
    "list-timezones",
    "List all available timezones",
    async () => {
      return {
        content: [{ 
          type: "text", 
          text: getFormattedTimezoneList()
        }]
      };
    }
  );

• src/server.ts:73-84 (registration)

  Registration of the 'list-timezones' tool using server.tool(), including its description and handler.

  server.tool(
    "list-timezones",
    "List all available timezones",
    async () => {
      return {
        content: [{ 
          type: "text", 
          text: getFormattedTimezoneList()
        }]
      };
    }
  );

• src/timezone-utils.ts:42-45 (helper)

  Helper function that formats the list of available timezones into a readable string, used by the list-timezones tool handler.

  export function getFormattedTimezoneList(prefix: string = "Available timezones"): string {
    const timezones = getAvailableTimezones();
    return `${prefix} (${timezones.length}): ${timezones.join(', ')}`;
  }

• src/timezone-utils.ts:22-35 (helper)

  Core helper that retrieves all available timezones using Intl.supportedValuesOf('timeZone'), adds common ones, sorts them, with fallback to COMMON_TIMEZONES.

  export function getAvailableTimezones(): string[] {
    try {
      const timezones = new Set<string>(Intl.supportedValuesOf('timeZone'));
      
      // Ensure common timezones are always included
      COMMON_TIMEZONES.forEach(tz => timezones.add(tz));
      
      return Array.from(timezones).sort();
    } catch (error) {
      console.error("Error getting timezones from Intl API:", error);
      // Fallback to common timezones if the Intl API fails
      return COMMON_TIMEZONES;
    }
  }

• src/timezone-utils.ts:2-16 (helper)

  Array of common timezones ensured to be available as fallback and for resource listing.

  export const COMMON_TIMEZONES = [
    "UTC",
    "Europe/London",
    "Europe/Paris",
    "Europe/Berlin",
    "America/New_York",
    "America/Chicago",
    "America/Denver",
    "America/Los_Angeles",
    "Asia/Tokyo",
    "Asia/Shanghai",
    "Asia/Kolkata",
    "Australia/Sydney",
    "Pacific/Auckland"
  ];