Month-separated blog post list in Jekyll w/ Liquid

list.html

---
layout: default
title: All Posts
category: blog
---
<div id="blog">
  <h2>{{page.title}}</h2>
  {% for post in site.categories.blog %}
    {% capture post_month %}{{post.date | date: "%m"}}{% endcapture %}
    {% if post_month != prev_post_month %}{% if prev_post_month %}</ol>{% endif %}<h3>{{post.date | date: "%B %Y"}}</h3><ol class="blog-list">{% endif %}
  	{% include blog-list-post.html %}
  	{% capture prev_post_month %}{{post_month}}{% endcapture %}
  {% endfor %}
</div>