sub format_cell {
    my ($self, $format, @days) = @_;
    
 	# @days lets you apply formatting to more 
	# than one date at a time.

    foreach (@days) {
        $self->{'cell_format'}[$_] = $format;
    }
}

##</code><code>##

sub format_cell2 {
    my ($self, $format, @days) = @_;
    
    foreach (@days) {
		foreach my $key (keys %$format) {
	    		${$self->{'cell_format'}[$_]}{$key} = 			                        ${$format}{$key};
		}
    }
}  

##</code><code>##

$html_months{$key} -> format_cell2({bgcolor => "red"}, 15)