世界完全对称日计算（C#）

原理很简单了，直接上代码了：

       //测试 

       static void Main(string[] args)
        {
            List<DateTime> result = GetSymmetryDate(Convert.ToDateTime("2000-01-01"), Convert.ToDateTime("3000-01-01"));
            foreach (DateTime datetime in result)
            {
                Console.WriteLine(datetime.ToString("yyyy-MM-dd"));
            }
        }
        static List<DateTime> GetSymmetryDate(DateTime startDate, DateTime endDate)
        {
            List<DateTime> result = new List<DateTime>();
            while (startDate <= endDate)
            {
                if (IsSymmetryDate(startDate))
                {
                    result.Add(startDate);
                }
                startDate = startDate.AddDays(1);
            }
            return result;
        }
        //判断是否为对称日 原理：年反转和月日匹配，匹配上了符合条件。
        static bool IsSymmetryDate(DateTime dateTime)
        {
            string dateYY = dateTime.ToString("yyyyMMdd").Substring(0, 4);
            string dateDDMM = dateTime.ToString("yyyyMMdd").Substring(4);
            char[] arr = dateYY.ToCharArray();
            Array.Reverse(arr);
            string temp = new string(arr);
            return dateDDMM == temp;
        }

 测试结果：

2001-10-02
2010-01-02
2011-11-02
2020-02-02
2021-12-02
2030-03-02
2040-04-02
2050-05-02
2060-06-02
2070-07-02
2080-08-02
2090-09-02
2101-10-12
2110-01-12
2111-11-12
2120-02-12
2121-12-12
2130-03-12
2140-04-12
2150-05-12
2160-06-12
2170-07-12
2180-08-12
2190-09-12
2201-10-22
2210-01-22
2211-11-22
2220-02-22
2221-12-22
2230-03-22
2240-04-22
2250-05-22
2260-06-22
2270-07-22
2280-08-22
2290-09-22