UserAgeFinal

static void Main()
        {
            Console.WriteLine("Enter user birthday: DD.MM.YYYY");
            string birthDay = Console.ReadLine();
            string userYear = birthDay.Substring(6, 4);
            int userYearInt = int.Parse(userYear);
            string userMonth = birthDay.Substring(3, 2);
            int userMonthInt = int.Parse(userMonth);
            string userDay = birthDay.Substring(0, 2);
            int userDayInt = int.Parse(userDay);

            switch (userMonthInt)
            {
                case 01:
                    {
                        string userMonthStr = "January";
                        userMonth = userMonthStr;
                        break;
                    }
                case 02:
                    {
                        string userMonthStr = "February";
                        userMonth = userMonthStr;
                        break;
                    }
                case 03:
                    {
                        string userMonthStr = "March";
                        userMonth = userMonthStr;
                        break;
                    }
                case 04:
                    {
                        string userMonthStr = "April";
                        userMonth = userMonthStr;
                        break;
                    }
                case 05:
                    {
                        string userMonthStr = "May";
                        userMonth = userMonthStr;
                        break;
                    }
                case 06:
                    {
                        string userMonthStr = "June";
                        userMonth = userMonthStr;
                        break;
                    }
                case 07:
                    {
                        string userMonthStr = "July";
                        userMonth = userMonthStr;
                        break;
                    }
                case 08:
                    {
                        string userMonthStr = "August";
                        userMonth = userMonthStr;
                        break;
                    }
                case 09:
                    {
                        string userMonthStr = "September";
                        userMonth = userMonthStr;
                        break;
                    }
                case 10:
                    {
                        string userMonthStr = "October";
                        userMonth = userMonthStr;
                        break;
                    }
                case 11:
                    {
                        string userMonthStr = "November";
                        userMonth = userMonthStr;
                        break;
                    }
                case 12:
                    {
                        string userMonthStr = "December";
                        userMonth = userMonthStr;
                        break;
                    }
                default:
                    {
                        Console.WriteLine("Wrong input.");
                        break;
                    }
            }

            Console.WriteLine("User birthday:\nYear: {0}\nMonth: {1}\nDay: {2}", userYear, userMonth, userDay);

            int currentYearInt = DateTime.Now.Year;
            Console.WriteLine("Current year is: {0}", currentYearInt);
            int currentMonthInt = DateTime.Now.Month;
            Console.WriteLine("Current month is: {0}", currentMonthInt);
            int currentDayInt = DateTime.Now.Day;
            Console.WriteLine("Current day is: {0}", currentDayInt);

            int userAge = 0;
            if (userMonthInt < currentMonthInt)
            {
                userAge = currentYearInt - userYearInt;
                Console.WriteLine("User age is: {0}", userAge);
            }
            else if (userMonthInt > currentMonthInt)
            {
                userAge = currentYearInt - userYearInt - 1;
                Console.WriteLine("User age is: {0}", userAge);
            }
            else
            {
                if (userDayInt < currentDayInt)
                {
                    userAge = currentYearInt - userYearInt;
                    Console.WriteLine("User age is: {0}", userAge);
                }
                else if (userDayInt > currentDayInt)
                {
                    userAge = currentYearInt - userYearInt - 1;
                    Console.WriteLine("User age is: {0}", userAge);
                }
                else
                {
                    userAge = currentYearInt - userYearInt;
                    Console.WriteLine("Happy Birthday! Your birthday is today and you are {0} years old!", userAge);
                }
            }
            int ageAfterTenYears = 0;
            ageAfterTenYears = userAge + 10;
            Console.WriteLine("After ten years user will be {0} years old.", ageAfterTenYears);
        }