DateTimeExtensionsFixture.cs

public static List<CultureTestParameter[]> StaticParameter => new List<CultureTestParameter[]>
{
    new CultureTestParameter[]
    {
        new CultureTestParameter
        {
            Culture = CultureInfo.CreateSpecificCulture("it-IT"),
            Actual = new DateTime(1988, 06, 05),
            Expected = "05 giugno 1988"
        }
    }
};