for my $e ($dom->find('span')->each) {
  if($e->text =~ /$mydate/ ){
    my $myhtml = $e->parent->parent->parent->text;
    # do stuff with $myhtml
  }
}

##</code><code>##

#!/usr/bin/env perl
use Modern::Perl;
use LWP::Simple;

my $date = $ARGV[0] || '4/23/012';
my $page =
get('http://staweb.sta.cathedral.org/departments/math/mhansen/public_html/1112hcal/1112hcal.htm');
die "Couldn't get page" unless $page;
my( $assignment ) = $page =~ m{ $date .+? <span .+?>(.+?)</span>\s*</p> }sx;
say $assignment;