C# 中时间的计算

        DateTime d1 = new DateTime(2004, 1, 1, 15, 36, 05);
        DateTime d2 = new DateTime(2004, 1, 1, 20, 16, 35);
        DateTime now = new DateTime();
        now = System.DateTime.Now;
        TimeSpan d3 = d2.Subtract(now);

        Label1.Text = "相差:"
        + d3.Days.ToString() + "天"
        + d3.Hours.ToString() + "小时"
        + d3.Minutes.ToString() + "分钟"
        + d3.Seconds.ToString() + "秒";