Creating a Custom Blog Template

I’d like to create a loop for my blog like the on on Alex Sexton’s site: https://alexsexton.com/blog/archives/

I’ve added a custom page template but can’t get the date to display only once.

Since my site is in a local development environment I’m unable to include a link.

Alex’s Liquid logic looks like this:

{% for post in site.posts reverse %}
{% capture this_year %}{{ post.date | date: "%Y" }}{% endcapture %}
{% unless year == this_year %}
{% assign year = this_year %}
<h2>{{ year }}</h2>
{% endunless %}
<article>
{% include archive_post.html %}
</article>
{% endfor %}

Any ideas how to recreate this in WordPress logic?