Add clever variable dates in footer

_includes/footer.html

@@ -6,7 +6,12 @@
     <a rel="license"
       href="https://creativecommons.org/licenses/by/4.0/">CC-BY</a>/<a
       href="/LICENSE">MIT</a>
-    {{ site.time | date: '%Y' }}
+    {% assign site_age =  site.git.first_commit.commit_date | date: '%Y' %}
+    {% assign page_age =  page.git.last_commit.commit_date | date: '%Y' %}
+    {{ site_age }}
+    {%- if site_age != page_age -%}
+      &ndash;{{ page_age }}
+    {% endif %}
     <span xmlns:cc="http://creativecommons.org/ns#"
       data-url="{{site.url}}{{page.url}}"
       property="cc:attributionName"
@@ -18,9 +23,16 @@
       href="https://github.com/georgewatson/georgewatson.me/commit/{{ site.git.last_commit.long_sha }}"
       title="{{ site.git.last_commit.message }}"
       >{{ site.git.last_commit.short_sha }}</a>
+      <small>({{ site.git.last_commit.commit_date | date: '%F' }})</small>
     &bull;
     <i class="fas fa-user-secret"></i>
     <a href="/privacy_policy">Privacy policy</a>
+    {% assign pages_list = (site.pages | sort: 'order') %}
+    {%- for node in pages_list -%}
+      {% if node.title contains 'Privacy' %}
+        <small>({{ node.git.last_commit.commit_date | date: '%F' }})</small>
+      {% endif %}
+    {%- endfor -%}
   </p>
   <p>
     <i class="fas fa-palette"></i>

_includes/related_posts.html

@@ -9,7 +9,8 @@ <h2>Related posts</h2>
 {%- assign minTags = 2 -%}
 
 {% comment %}
-  Probably don't play with anything after this point
+  Probably don't play with anything after this point,
+  except that you may wish to reduce maxTags if compilation is slow
 {% endcomment %}
 {%- assign maxTags = page.tags | size -%}
 {%- assign relatedCount = 0 -%}
@@ -38,7 +39,7 @@ <h2>Related posts</h2>
 {%- for numTags in (minTags..maxTags) reversed -%}
   {%- for post in site.posts -%}
     {%- unless page.related contains post.url -%}
-      {%- if relatedCount < maxRelated and page.url != post.url -%}
+      {%- if relatedCount < maxRelated and page.id != post.id -%}
         {%- assign sharedTags = 0 -%}
         {%- for tag in post.tags -%}
           {%- if page.tags contains tag -%}
@@ -65,7 +66,7 @@ <h2>Related posts</h2>
 {%- if relatedCount < maxRelated -%}
   {%- for post in site.posts -%}
     {%- unless page.related contains post.url -%}
-      {%- if relatedCount < maxRelated and page.url != post.url and page.category == post.category -%}
+      {%- if relatedCount < maxRelated and page.id != post.id and page.category == post.category -%}
         {%- assign sharedTags = 0 -%}
         {%- for tag in post.tags -%}
           {%- if page.tags contains tag -%}