NUMBER OF DAYS IN A YEAR / MECIES

static void Main(string[] args)
        {
            Console.WriteLine("Give me a year");
            int given_year = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("Give me a number representation of a month:" +
                "\n1 - January, March, May, July, August, October, December" +
                "\n2 - April, June, Septempber, November\n3 - February");
            int month = Convert.ToInt32(Console.ReadLine());
            Number_Of_Days(given_year, month);
            Console.ReadKey();
        }

        public static int Number_Of_Days(int given_year, int month_number)
        {
            if(given_year % 4 == 0 && given_year % 100 != 0 || (given_year % 400 == 0))
            {
                Console.WriteLine(given_year + " is a leap year");
                if(month_number == 1)
                {
                    Console.WriteLine("Number of days: 31");
                }
                if(month_number == 2)
                {
                    Console.WriteLine("Number of days: 30");
                }
                if(month_number == 3)
                {
                    Console.WriteLine("Number od days: 29");
                }
                return given_year;
            }

            else
            {
                Console.WriteLine(given_year + " is a leap year");
                if (month_number == 1)
                {
                    Console.WriteLine("Number of days: 31");
                }
                if (month_number == 2)
                {
                    Console.WriteLine("Number of days: 30");
                }
                if (month_number == 3)
                {
                    Console.WriteLine("Number od days: 28");
                }
                return given_year;
            }
        }