Built-in function FormatDateTime() is not taking the Current Locale into account. To show the months in another language additional logic or JavaScript is needed. It would be great when the "desired" locale can be optionally added as input parameter to the FormatDateTime issue, providing an output in the desired language.
Example:

In above exampe standard JavaScript function date.toLocaleString(locale, options) is just to "convert" the date to a different language.