DateTime-sample.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;

namespace DateTimeSample01
{
    public class Program
    {
        public static void Main(string[] args)
        {
            DateTime hoge = new DateTime(2017, 4, 10);
            TimeSpan piyo = new TimeSpan(26, 0, 0);
            hoge = hoge.Add(piyo);
            // 2017/04/11 02:00:00
        }
    }
}