use Mojo::DOM;
my $dom = Mojo::DOM->new();
$|=1;
my $test1=$dom->parse('<a class="ab">2016-05-18</a>')->at('a.ab')->text;
print "$test1\n";
my $test2=$dom->parse('<a class="a b">2016-05-18</a>')->at('a.a b')->text;
print "$test2\n";