try this
DateTime db;
Console.WriteLine("Enter Date in this Format(DD-MM-YYYY):");
string input = Console.ReadLine();
string[] formats = { "d-M-yyyy", "d-MM-yyyy", "dd-M-yyyy", "dd-MM-yyyy" };
db = DateTime.ParseExact(input, formats, System.Globalization.CultureInfo.InvariantCulture, System.Globalization.DateTimeStyles.None);
for parsing with validation use this
if (DateTime.TryParseExact(input, formats, System.Globalization.CultureInfo.InvariantCulture, System.Globalization.DateTimeStyles.None, out db))
{
DateTime date = db;
}