ตรวจสอบว่าเป็น ค.ศ., พ.ศ.

  procedure TFormXX.FormCreate(Sender: TObject);
  var
    O: PChar;
    S: LCID;
    c: Integer;
  begin

    O := StrAlloc(255);
    S := GetUserDefaultLCID;

    GetLocaleInfo(S, LOCALE_ICALENDARTYPE, O, 255);
    Caption := 'Native language for user locale is ' + O;

    C := StrToInt(WideCharToString(O));

    case C of
      0:      ShowMessage('None');
      1:      ShowMessage('Gregorian');
      3:      ShowMessage('Japanese Emperor Era');
      5:      ShowMessage('Korean Tangun Era');
      6:      ShowMessage('Hijri');
      7:      ShowMessage('Buddhist');
      8:      ShowMessage('Hebrew Lunar');
      9:      ShowMessage('Gregorian Middle East French Calendar');
      10:     ShowMessage('Gregorian Arabic Calendar');
      11:     ShowMessage('Gregorian Transliterated English Calendar');
      12:     ShowMessage('Gregorian Transliterated French Calendar');
      16:     ShowMessage('Saka Era');
    end;

    StrDispose(O);

  end;