测试日期时间的时间部分，每天的8点---10点之间

using System;
using System.Collections.Generic;
using System.Text;namespace TestDatetimeSubtract
{
    class Program
    {
        static void Main(string[] args)
        {
            //只测试日期时间的时间部分，每天的8点---10点之间
            DateTime PushStartTime = new DateTime(2017, 3, 1, 8, 0, 0);
            DateTime PushEndTime = new DateTime(2017, 3, 1, 10, 0, 0);
            long ss = DateTime.Now.TimeOfDay.Subtract(PushStartTime.TimeOfDay).Ticks;
            long ss1 = DateTime.Now.TimeOfDay.Subtract(PushEndTime.TimeOfDay).Ticks;
            if (DateTime.Now.TimeOfDay.Subtract(PushStartTime.TimeOfDay).Ticks > 0 
                && DateTime.Now.TimeOfDay.Subtract(PushEndTime.TimeOfDay).Ticks < 0)
            {
                Console.WriteLine("ok");
            }
            Console.Read();
        }
    }
}