{% comment %}
  Get the last 5 posts from lastmod list.
  v2.2
  https://github.com/cotes2020/jekyll-theme-chirpy
  © 2020 Cotes Chung
  MIT License
{% endcomment %}

{% assign MAX_SIZE = 5 %}

{% assign all_list = "" | split: "" %}

{% for post in site.posts %}
  {% if post.lastmod %}
    {% capture elem %}
      {{- post.lastmod | date: "%Y%m%d%H%M%S" -}}::{{- forloop.index0 -}}
    {% endcapture %}
    {% assign all_list = all_list | push: elem %}
  {% endif %}
{% endfor %}

{% assign all_list = all_list | sort | reverse %}

{% assign update_list = "" | split: "" %}

{% for entry in all_list limit:MAX_SIZE %}
  {% assign update_list = update_list | push: entry %}
{% endfor %}