use strict;
use XML::Rules;
use Data::Dumper;

my $parser = XML::Rules->new(
	strispaces => 7,
	rules => {
		Time => 'as array',
		Times => 'pass',
		'Day' => sub {
			my ($tag_name, $attrs, $context, $parent_data, $parser) = @_;
			if ($attrs->{'day-of-week'} eq $parser->{parameters}) {
				$parser->return_this(join(', ', grep( defined($_), map $_->{'start-time'}, @{$attrs->{Time}})));
			}
		},
		Month => sub{}
	}
);

my $time = $parser->parse(\*DATA, 'MondayX');

print "Time: $time\n";


__DATA__
<?xml version="1.0" encoding="utf-8"?>
  <Month>
    <Week>