Вот простой способ запрета издевательств, который я написал для вас в своем блоге, предполагая, что вы используете ValueProvider, а не HttpContext: http://www.hanselman.com/blog/SplittingDateTimeUnitTestingASPNETMVCCustomModelBinders.aspx
[TestMethod]
public void DateTime_Can_Be_Pulled_Via_Provided_Month_Day_Year_Hour_Minute_Second_Alternate_Names()
{
var dict = new ValueProviderDictionary(null) {
{ "foo.month1", new ValueProviderResult("2","2",null) },
{ "foo.day1", new ValueProviderResult("12", "12", null) },
{ "foo.year1", new ValueProviderResult("1964", "1964", null) },
{ "foo.hour1", new ValueProviderResult("13","13",null) },
{ "foo.minute1", new ValueProviderResult("44", "44", null) },
{ "foo.second1", new ValueProviderResult("01", "01", null) }
};
var bindingContext = new ModelBindingContext() { ModelName = "foo", ValueProvider = dict };
DateAndTimeModelBinder b = new DateAndTimeModelBinder() { Month = "month1", Day = "day1", Year = "year1", Hour = "hour1", Minute = "minute1", Second = "second1" };
DateTime result = (DateTime)b.BindModel(null, bindingContext);
Assert.AreEqual(DateTime.Parse("1964-02-12 13:44:01"), result);
}