system.datatime 与system.timespan

        static void Main(string[] args)
        {
            Console.WriteLine("*********");

            UseDatesAndTimes();


            Console.ReadLine();
        }

        private static void UseDatesAndTimes()
        {
            DateTime dt = new DateTime(2010, 10, 17);
            //一个月中的哪一天
            Console.WriteLine("tht day of {0},is {1}", dt.Date, dt.DayOfWeek);
            //增加月份
            dt = dt.AddMonths(2);
            Console.WriteLine("day light saving {0};{1}", dt.IsDaylightSavingTime(),dt.Month);

            //构造函数接受小时，分钟，秒
            TimeSpan ts = new TimeSpan(4, 30, 0);
            Console.WriteLine(ts);
            //从当前减去15分钟
            Console.WriteLine(ts.Subtract(new TimeSpan(0,15,0)));



        }