WP - Create collapsable date indented archive list

Right now I have category titles listed by date like this...

01-01 - Cat Title
02-01 - Cat Title 2
02-01 - Cat Title 2
03-01 - Cat Title 3

The working code for this is ...

$posts = get_posts(array(
    'posts_per_page'    => -1,
    'post_type'         => 'post',
    'order'             => 'DESC',
    'orderby'           => 'date',
    'tag'               => 'editorial'
));

if( $posts ): ?>

    <ul>

       <?php  
       foreach( $posts as $post ): setup_postdata( $post ) ?>
          <li> 
          <div>
          <?php
            single_cat_title( '', true );

          ?>
          </div>
          <div>
            <?php echo get_the_date('m-Y');?><?php echo (' - ');?><a href="<?php the_permalink(); ?>" rel="bookmark" title="<?php the_title_attribute(); ?>"><?php the_title(); ?></a>
          </div>
          </li> 
       <?php endforeach; ?>

  </ul>

I'd like for the list to look like this when all dates are open...

01-01 - Cat Title
02-01 - Cat Title 2
           - Cat Title 2
03-01 - Cat Title 3

And like this when all dates are closed...
01-01
02-01
03-01

There are plenty of plugins that do this but none that list titles with a specific tag, it would be amazing to have this solved.

via Chebli Mohamed