Liquid Template language to group jekyll blog posts by year.

group_posts_by_year_jekyll.html

{% for post in site.posts %} 
  {% capture current_year %}
    {{post.date | date: "%Y"}}
  {% endcapture %} 
  {% if current_year != previous_year %} 
    {% assign previous_year = current_year %}
    <h4 class="post-header">
      <span role="img" aria-label="icon-book" aria-hidden="true">🎉</span>
      {{ current_year }}
    </h4>
  {% endif %}
  <article class="posts">
    <span class="posts-date">{{ post.date | date: "%b %d" }}</span>
    <header class="posts-header">
      <h4 class="posts-title">
        <a href="{{ post.url }}">{{ post.title | escape }}</a>
      </h4>
    </header>
  </article>
{% endfor %}