private String twoDigit(final int day) {
        final int ten = 10;
        if (day >= ten) {
            return Integer.toString(day);
        }
        return "0" + day;
    }
private String twoDigit ( final int day ) { final int ten = 10 ; if ( day >= ten ) { return Integer . toString ( day ) ; } return "0" + day ; }
@param day a day number
@return as a two digit string