Converting String to datetime format

Question

I have a String which is in 04-DEC-78 format, I want it to be inserted in to a field in sql database.If I map directly I am getting
"Microsoft.ServiceModel.Channels.Common.XmlReaderParsingException: The input data for the field/parameter "e_date" is invalid according to the expected SqlDbType DateTime. ---> System.FormatException: The string '04-DEC-65' is not a valid
AllXsd value.
Tried to convert the string to datetime format in Mapping but getting error
public DateTime FormatCheck(string param1)
IFormatProvider culture = new CultureInfo("en-US", true);
return  DateTime.ParseExact(param1, "dd/MM/yyyy HH:mm:ss.fff", culture);
Inline Script Error: The type or namespace name 'CultureInfo' could not be found (are you missing a using directive or an assembly reference?) 
Help me out!!

Answer 1

HOLD ON!
Let's try to clear this up. If the input data is "04-DEC-78" then, sorry, none of the code posted so far will work.
"04-DEC-78" is not directly parsable so the .ParseExact format must match the source.
The format for xs:datetime is ISO 8601 which is like yyyy-MM-ddTHH:mm:ss-[offset].  Internally the sqlBinding will cast the XsdDateTime (the .Net xs:datetime implementation) to a SqlDateTime.
One very, very important missing detail is the type of the SQL parameter.  Is it (SQL) datetime or string?
If the SQL parameter is datetime, then you can use this:
public string FormatCheck(string param1)
return DateTime.ParseExact(param1, "dd-MMM-yy", System.Globalization.CultureInfo.InvariantCulture).ToString("s");