What "neutral culture" breaks DateTime.TryParse()?

Question

I have the following code snippet

DateTime date1;
CultureInfo neutralCulture = new CultureInfo("fr");
bool isNeutral = neutralCulture.IsNeutralCulture; // True

DateTime.TryParse("not a date", neutralCulture, DateTimeStyles.AdjustToUniversal, out date1);

Which executes without throwing an exception, however, the documentation states

NotSupportedException: provider is a neutral culture and cannot be used in a parsing operation.

"fr" is a neutral culture, as demonstrated by the property on the CultureInfo object above, so I would expect this code to break.

What "neutral culture" breaks this method - is this documented anywhere?

Answer 1

I did a quick test of all the neutral cultures, and not even one threw an exception as shown below:

CultureInfo[] cultures = CultureInfo.GetCultures(CultureTypes.NeutralCultures);
foreach (var thisCulture in cultures)
{
    DateTime date1;
    CultureInfo neutralCulture = new CultureInfo(thisCulture.Name);
    bool isNeutral = neutralCulture.IsNeutralCulture; // True

    DateTime.TryParse("not a date", neutralCulture, DateTimeStyles.AdjustToUniversal, out date1);
}

I am not sure what to conclude from that. Could the documentation be wrong? Who knows.