class Program
{
    static void Main(string[] args)
    {
        DateTime dt = DateTime.Now;
        Console.WriteLine("当前日期为：{0}", dt);
        Console.WriteLine("当前时本月的第{0}天", dt.Day);
        Console.WriteLine("当前是：{0}", dt.DayOfWeek);
        Console.WriteLine("当前是本年度第{0}天", dt.DayOfYear);
        Console.WriteLine("30 天后的日期是{0}", dt.AddDays(30));
    }
}

class Program
{
    static void Main(string[] args)
    {
        DateTime dt1 = DateTime.Now;
        DateTime dt2 = new DateTime(2019, 6, 1);
        TimeSpan ts = dt2 - dt1;
        Console.WriteLine("间隔的天数为{0}天", ts.Days);
    }
}