[c#] DateTime and CultureInfo

InvariantCulture is similar to en-US, so i would use the correct CultureInfo instead:

var dutchCulture = CultureInfo.CreateSpecificCulture("nl-NL");
var date1 = DateTime.ParseExact(date, "dd.MM.yyyy HH:mm:ss", dutchCulture);

Demo

And what about when the culture is en-us? Will I have to code for every single language there is out there?

If you want to know how to display the date in another culture like "en-us", you can use date1.ToString(CultureInfo.CreateSpecificCulture("en-US")).