docs: def tz_path(name):
      """
      Return the path to a timezone file.
  
      :param name: The name of the timezone.
      :type name: str
  
      :rtype: str
      """
      if not name:
          raise ValueError('Invalid timezone')
  
      name_parts = name.lstrip('/').split('/')
  
      for part in name_parts:
          if part == os.path.pardir or os.path.sep in part:
              raise ValueError('Bad path segment: %r' % part)
  
      filepath = os.path.join(_DIRECTORY, *name_parts)
  
      if not os.path.exists(filepath):
          raise TimezoneNotFound('Timezone {} not found at {}'.format(name, filepath))
  
      return filepath