My age after 10 years

using System;
// Write a program to read your birthday from the console and print how old you are now and how old you will be after 10 years.
class AgeAfter10Years
{
    static void Main()
    {
        Console.WriteLine("Please enter your birthday (ex. DD/MM/YY): ");
        DateTime birthDay = new DateTime();
        birthDay = DateTime.Parse(Console.ReadLine());
        DateTime currentDay = DateTime.Now;
        int myAge = (DateTime.Now.Year - birthDay.Year);
        if (birthDay.Year > currentDay.Year || birthDay.Year == currentDay.Year)
        {
            Console.WriteLine("You are not born!");
        }
        else if (currentDay.DayOfYear < birthDay.DayOfYear)
        {
            myAge--;
            Console.WriteLine("After 10 years you will be {0} years old", myAge + 10);
        }
        else if (birthDay.DayOfYear == currentDay.DayOfYear)
        {
            Console.WriteLine("After 10 years you will be {0} years old", myAge + 10);
            Console.WriteLine("Happy birthday!");
        }
        else
        {
            Console.WriteLine("After 10 years you will be {0} years old.", myAge + 10);
        }

    }
}