code: def get_local_tz():
      """
      Get the named local timezone that the VegaFusion mimetype renderer
      will use for calculations.
  
      Defaults to the kernel's local timezone as determined by vl-convert.
  
      Has no effect on VegaFusionWidget, which always uses the
      browser's local timezone
  
      :return: named timezone string
      """
      if __tz_config["local_tz"] is None:
          # Fall back to getting local_tz from vl-convert if not set
          try:
              import vl_convert as vlc
  
              __tz_config["local_tz"] = vlc.get_local_tz() or "UTC"
          except ImportError:
              raise ImportError(
                  "vl-convert is not installed and so the local system timezone cannot be determined.\n"
                  "Either install the vl-convert-python package or set the local timezone manually using\n"
                  "the vegafusion.set_local_tz function"
              )
  
      return __tz_config["local_tz"]
  
label_desc: Use image node_id 1 for calling a global function with example usage: get_local_tz() and returns: __tz_config