Lastmod is autopopulated from Date if not set.

layouts/_default/list.json.json

@@ -26,11 +26,7 @@
     {
         "title" : {{ .Title | jsonify }},
         "date_published" : "{{ .Date.Format "2006-01-02T15:04:05Z07:00" }}",
-        {{ if .Lastmod -}}
-        "date_modified" : "{{ .Date.Format "2006-01-02T15:04:05Z07:00" }}",
-        {{ else -}}
-        "date_modified" : "{{ .LastMod.Format "2006-01-02T15:04:05Z07:00" }}",
-        {{ end -}}
+        "date_modified" : "{{ .Lastmod.Format "2006-01-02T15:04:05Z07:00" }}",
         "id" : "{{ .Permalink }}",
         "url" : "{{ .Permalink }}",
         {{ with .Params.author -}}

layouts/_default/single.html

@@ -13,7 +13,7 @@
 <div class="content">
 {{ .Content }}
 
-{{ if not .Lastmod.IsZero }}{{ partial "dates.html" . }}{{ end -}}
+{{ if ne .Lastmod .Date }}{{ partial "dates.html" . }}{{ end -}}
 </div>
 </article>
 </main>

layouts/partials/submitted.html

@@ -1,8 +1,4 @@
 <p class="submitted">
 {{ with $.Param "author" }}<span class="author">{{ . }}</span> – {{ end -}}
-{{ if not .Lastmod.IsZero -}}
 <time class="modified-date" datetime="{{ .Lastmod.Format "2006-01-02T15:04:05Z07:00" }}">{{ .Lastmod.Format ($.Param "dateformat" | default "2 January, 2006") }}</time>
-{{ else -}}
-<time class="modified-date" datetime="{{ .Date.Format "2006-01-02T15:04:05Z07:00" }}">{{ .Date.Format ($.Param "dateformat" | default "2 January, 2006") }}</time>
-{{ end -}}
 </p>