-@item hls_init_time @var{seconds}
-Set the initial target segment length in seconds. Default value is @var{0}.
+@item hls_init_time @var{duration}
+Set the initial target segment length. Default value is @var{0}.
+
+@var{duration} must be a time duration specification,
+see @ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}.
+