using System;

using System.Globalization;

​

public class Program

{

    public static void Main()

    {

        String assignedDate1 = "21-11-2018";

        String assignedDate2 = "22-11-2018";

        String assignedDate3 = null;

        String assignedDate4 = "22.11.2018";

        String assignedDate5 = "helloWorld";

        DateTime dt1;

        DateTime dt2;

        DateTime dt3;

        DateTime dt4;

        DateTime dt5;

        if (!DateTime.TryParseExact(assignedDate1, "dd-MM-yyyy", null, DateTimeStyles.None, out dt1))

        {

            dt1 = DateTime.MaxValue;

        }

​

        Console.WriteLine(dt1.ToString());

        if (!DateTime.TryParseExact(assignedDate2, "dd-MM-yyyy", null, DateTimeStyles.None, out dt2))

        {

            dt2 = DateTime.MaxValue;

        }

​

        Console.WriteLine(dt2.ToString());

        if (!DateTime.TryParseExact(assignedDate3, "dd-MM-yyyy", null, DateTimeStyles.None, out dt3))

        {

            dt3 = DateTime.MaxValue;

        }

​

        Console.WriteLine(dt3.ToString());

        if (!DateTime.TryParseExact(assignedDate4, "dd-MM-yyyy", null, DateTimeStyles.None, out dt4))

        {

            dt4 = DateTime.MaxValue;

        }

​

        Console.WriteLine(dt4.ToString());

        if (!DateTime.TryParseExact(assignedDate5, "dd-MM-yyyy", null, DateTimeStyles.None, out dt5))

        {

            dt5 = DateTime.MaxValue;

        }

​

        Console.WriteLine(dt5.ToString());

        Console.WriteLine("DateTime.Compare(dt1, dt2) :" + DateTime.Compare(dt1, dt2));

        Console.WriteLine("DateTime.Compare(dt1, dt3) :" + DateTime.Compare(dt1, dt3));

        Console.WriteLine("DateTime.Compare(dt1, dt4) :" + DateTime.Compare(dt1, dt4));

        Console.WriteLine("DateTime.Compare(dt1, dt5) :" + DateTime.Compare(dt1, dt5));

        Console.WriteLine("DateTime.Compare(dt2, dt1) :" + DateTime.Compare(dt2, dt1));

        Console.WriteLine("DateTime.Compare(dt2, dt3) :" + DateTime.Compare(dt2, dt3));

        Console.WriteLine("DateTime.Compare(dt2, dt4) :" + DateTime.Compare(dt2, dt4));

        Console.WriteLine("DateTime.Compare(dt2, dt5) :" + DateTime.Compare(dt2, dt5));

        Console.WriteLine("DateTime.Compare(dt3, dt1) :" + DateTime.Compare(dt3, dt1));

        Console.WriteLine("DateTime.Compare(dt3, dt2) :" + DateTime.Compare(dt3, dt2));

        Console.WriteLine("DateTime.Compare(dt3, dt4) :" + DateTime.Compare(dt3, dt4));

        Console.WriteLine("DateTime.Compare(dt3, dt5) :" + DateTime.Compare(dt3, dt5));

    }

}