Question

my string format are in M/d/yyyy. Which means there will be no zero in front of the month and date digit.
example: 9/23/2012, 7/9/2012 etc

I have tried:

^((((0?[1-9]|[12]\d|3[01]).-/.-/)|((0?[1-9]|[12]\d|30).-/.-/)|((0?[1-9]|1\d|2[0-8])[.-/]0?2.-/)|(29[.-/]0?2.-/))|(((0[1-9]|[12]\d|3[01])(0[13578]|1[02])((1[6-9]|[2-9]\d)?\d{2}))|((0[1-9]|[12]\d|30)(0[13456789]|1[012])((1[6-9]|[2-9]\d)?\d{2}))|((0[1-9]|1\d|2[0-8])02((1[6-9]|[2-9]\d)?\d{2}))|(2902((1[6-9]|[2-9]\d)?(0[48]|[2468][048]|[13579][26])|((16|[2468][048]|[3579][26])00)|00))))$

but i guess this is for d/M/yyyy.

Anyone have the expression for M/d/yyyy?

Answer 1

If you are trying to validate if the Date is in format M/d/yyyy then DateTime.TryParseExact is a better solution then Regex. Something like.

string str = "9/23/2012";
DateTime dt;
if(DateTime.TryParseExact(str,
                          "M/d/yyyy",
                          CultureInfo.InvariantCulture,
                          DateTimeStyles.None, 
                          out dt))
{
    //valid date
}
else
{
    //Invalid date
}