Special chars with lang.format

Hello,

I am making a watch face and I am encountering an issue with special chars to write the month name (august => août in French). 

On the sim, the "û" letter is not displayed correctly. The encoding of all the files is "UTF-8". 

dc.drawText( (WIDTH / 2)-60, ((HEIGHT/2)-50), Graphics.FONT_SYSTEM_XTINY,getDate(), Graphics.TEXT_JUSTIFY_CENTER);

    //get the date
    private function getDate() as String {
    var today = Gregorian.info(Time.now(), Time.FORMAT_MEDIUM);
    
    var dateString = Lang.format("$1$ $2$ $3$",         [
                today.day_of_week,
                today.day,
                today.month,
            ]
        );
        return dateString;
}

To check where the issue comes from I tried :

- using a System.println("dateString"); and the debug console doesn't show the expected chars.

- replace the line : 

dc.drawText( (WIDTH / 2)-60, ((HEIGHT/2)-50), Graphics.FONT_SYSTEM_XTINY,getDate(), Graphics.TEXT_JUSTIFY_CENTER);

by 

dc.drawText( (WIDTH / 2)-60, ((HEIGHT/2)-50), Graphics.FONT_SYSTEM_XTINY,"û", Graphics.TEXT_JUSTIFY_CENTER);

  I can read "û" chars on the sim.

Can anyone explain me the stuff that I have to change in order to edit the special char with success please?

I thank you in advance,

Christophe