seconds.r8.v = delta_time(new_start_time.i4.v)

	This function will return a delta time in seconds since the
	last time that this routine was called or the last time that
	the start time was set.  The first call to this routine in
	a program always sets the start time and returns a value
	of 0.0.

	start_new_time	flag indicating whether or not to reset the
			start time

	This function returns status values as follows:

	delta time in seconds

	This function requires the following include files:


	Related functions:

	delta_time_history, delta_time_private, delta_time_allocate,
	delta_time_free, delta_time_history_private

	C/C++ usage:

	int	new_start_time = TRUE;
	double	seconds;

	seconds = delta_time(new_start_time);