public static void Main()
string date = DateTime.Now.ToString("yyyy/M/dd ");
string time = DateTime.Now.ToString("hh:mm:ss");
Console.WriteLine(Convert.ToDateTime(date+time).ToString("yyyy/MM/dd HH:mm:ss"));
Console.WriteLine(DateTime.ParseExact(date+time, "yyyy/M/dd hh:mm:ss",null).ToString("yyyy/MM/dd hh:mm:ss"));