my %month_names = do {
    my $i = 1;
    map { sprintf("%02d", $i++) => $_ } qw(
        January Feburary March
        April May June
        July August September
        October November December
    )
};

sub get_monthname
{
    my ($month_num) = @_;

    $month_num = sprintf("%02d", $month_num);
    return $month_names{$month_num};
}