/// <summary>
/// 返回一个新的时段对象，其值为指定的时段对象与此实例的值之差。
/// </summary>
/// <param name="span">时段</param>
/// <returns>新的时段</returns>
public GnssTimeSpan Subtract(GnssTimeSpan span)
{
GnssTime time = _end;
time.AddSeconds(-span.TotalSeconds);
return(new GnssTimeSpan(_start, time));
}
/// <summary>
/// 时段中是否包含某个时段
/// </summary>
/// <param name="span">时段</param>
/// <returns>是否在其中</returns>
public bool Contains(GnssTimeSpan span)
{
return((_end.CompareTo(span.End) >= 0) && (_start.CompareTo(span.Start) <= 0));
}