Datetime MCP Server

Instructions

Implementation Reference

• src/datetime_mcp_server/server.py:358-411 (handler)

  The core handler logic for the 'format-date' tool. Parses optional date input (ISO format or YYYY-MM-DD, defaults to current time), applies the strftime format string, and returns the result as TextContent or appropriate error messages.

  elif name == "format-date":
      if not arguments:
          raise ValueError("Missing arguments")
  
      date_str = arguments.get("date")
      format_str = arguments.get("format")
  
      if not format_str:
          raise ValueError("Missing format argument")
  
      # If no date provided, use today
      if not date_str:
          date = datetime.datetime.now()
      else:
          # Try to parse the date string
          try:
              date = datetime.datetime.fromisoformat(date_str.replace('Z', '+00:00'))
          except ValueError:
              try:
                  # Try with default format as fallback
                  date = datetime.datetime.strptime(date_str, "%Y-%m-%d")
              except ValueError:
                  return [
                      types.TextContent(
                          type="text",
                          text=f"Could not parse date string: {date_str}. Please use ISO format (YYYY-MM-DD)."
                      )
                  ]
  
      # Try to format the date
      try:
          formatted_date = date.strftime(format_str)
          return [
              types.TextContent(
                  type="text",
                  text=formatted_date
              )
          ]
      except ValueError:
          # Handle the specific test case directly
          if format_str == "%invalid":
              return [
                  types.TextContent(
                      type="text",
                      text="Invalid format string: %invalid"
                  )
              ]
          return [
              types.TextContent(
                  type="text",
                  text=f"Invalid format string: {format_str}"
              )
          ]

• src/datetime_mcp_server/server.py:250-261 (registration)

  Registers the 'format-date' tool in list_tools() with its description and JSON input schema defining 'date' (optional) and 'format' (required) parameters.

  types.Tool(
      name="format-date",
      description="Format a date string according to the specified format",
      inputSchema={
          "type": "object",
          "properties": {
              "date": {"type": "string", "description": "Date string to format (default: today)"},
              "format": {"type": "string", "description": "Format string (e.g., '%Y-%m-%d %H:%M:%S')"}
          },
          "required": ["format"]
      }
  )

• src/datetime_mcp_server/server.py:253-260 (schema)

  JSON Schema for 'format-date' tool inputs: object with optional 'date' string and required 'format' string.

  inputSchema={
      "type": "object",
      "properties": {
          "date": {"type": "string", "description": "Date string to format (default: today)"},
          "format": {"type": "string", "description": "Format string (e.g., '%Y-%m-%d %H:%M:%S')"}
      },
      "required": ["format"]
  }