Checking Date format from a string in C#

string inputString = "2000-02-02";
DateTime dDate;

if (DateTime.TryParse(inputString, out dDate))
{
    String.Format("{0:d/MM/yyyy}", dDate); 
}
else
{
    Console.WriteLine("Invalid"); // <-- Control flow goes here
}

you can use DateTime.ParseExact with the format string

DateTime dt = DateTime.ParseExact(inputString, formatString, System.Globalization.CultureInfo.InvariantCulture);

Above will throw an exception if the given string not in given format.

use DateTime.TryParseExact if you don't need exception in case of format incorrect but you can check the return value of that method to identify whether parsing value success or not.

check Custom Date and Time Format Strings

I think one of the solutions is to use DateTime.ParseExact or DateTime.TryParseExact

DateTime.ParseExact(dateString, format, provider);

source: http://msdn.microsoft.com/en-us/library/w2sa9yss.aspx