using System;

public class Program

{

    public static void Main()

    {

        DateTime dt = new DateTime(2017, 1, 1);

        DateTime dt1 = new DateTime(2017, 1, 8);

        DateTime dt2 = new DateTime(2017, 1, 2);

        DateTime dt3 = new DateTime(2016, 1, 1);

        Console.WriteLine( string.Format("The date before was {0}", dt) );

        DateTime dtAdd = dt.AddDays(-2);

        Console.WriteLine( string.Format("The date after was {0}", dtAdd) );

        int compareResult = dt.CompareTo(dtAdd);  

        if (compareResult < 0)  

        Console.WriteLine(dt +" is earlier than "+ dtAdd);  

        else if (compareResult == 0)  

        Console.WriteLine("Both dates are same");  

        else  

        Console.WriteLine(dt +" is later than "+ dtAdd);

        Console.WriteLine("Comparer result: " + compareResult); 

        Console.WriteLine(); 

        int compareResult1 = dt.CompareTo(dt1); 

        if (compareResult1 < 0)  

        Console.WriteLine(dt +" is earlier than "+ dt1);  

        else if (compareResult1 == 0)  

        Console.WriteLine("Both dates are same");  

        else  

        Console.WriteLine(dt +" is later than "+ dt1); 

        Console.WriteLine("Comparer result: " + compareResult1);  

        Console.WriteLine(); 

        Console.WriteLine(dt1+ " substracting " + dt);

        Console.WriteLine("Substraction method result: "+ ((dt1 - dt).TotalDays));

    }

}