A natural duration is the period of a single iteration. If this method returns Automatic it means that the natural duration is unknown. In this case, the NaturalDuration of the Clock is determined by the author. For example, the duration of streaming media would be determined by the provider of the streaming media.
Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)