{% for post in site.posts %}
{% assign post_month_year = post.date | date: "%B %Y" %}
{% assign newer_post_month_year = post.next.date | date: "%B %Y" %}
{% if post_month_year != newer_post_month_year %}
<div class="archive-title"><strong>
{{ post_month_year }}
</strong></div>
{% endif %}
<li>
{% comment %}
{{ post.date | date_to_string }} » [ {{ post.title }} ]({{ post.url }})
{% endcomment %}
{{ post.date | date_to_string }} »
<a href="{{ post.url }}">
{{ post.title }}
</a>
</li>
{% endfor %}
</ul>