/// <summary>
/// Subtracts RisingTimeSpan from the FloatingDateTime. The result is a stationary DateTime since the floating component of both inputs is cancelled out.
/// </summary>
/// <param name="timespan">RisingTimeSpan to subtract from the FloatingDateTime.</param>
/// <returns>Point in time equal to subtracting RisingTimeSpan's Snapshot property from FloatingDateTime's Snapshot property.</returns>
public DateTime Subtract(RisingTimeSpan timespan)
{
CheckZone(timespan);
return(timespan.ZeroMoment + _delta);
}
public TimeSpan Add(RisingTimeSpan other)
{
return(_zero - other.ZeroMoment);
}
