code: def get_iana_tz(windows_tz):
      
      timezone = WIN_TO_IANA.get(windows_tz)
      if timezone is None:
          # Nope, that didn't work. Try adding "Standard Time",
          # it seems to work a lot of times:
          timezone = WIN_TO_IANA.get(windows_tz + ' Standard Time')
  
      # Return what we have.
      if timezone is None:
          raise pytz.UnknownTimeZoneError(
              "Can't find Windows TimeZone " + windows_tz)
  
      return timezone
docs: Returns a valid pytz TimeZone (Iana/Olson Timezones) from a given
      windows TimeZone
  
      :param windows_tz: windows format timezone usually returned by
       microsoft api response
      :return:
      :rtype: