From d6cc7839ef0f0616e360719f2d8a735f9e430a44 Mon Sep 17 00:00:00 2001
From: Alan Orth <alan.orth@gmail.com>
Date: Sun, 22 Jan 2017 14:58:13 +0200
Subject: [PATCH] layouts/_default/list.html: Use .Date for modification time
 on nodes
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I'm not sure if it really matters to bots who will parse this (it's
much more important on content pages of course), but using .Date on
nodes like the homepage and taxonomy terms pages will set the date
to be that of the latest post in that range—to me this does indeed
seem to be "time when the object was last updated"[0].

[0] https://developers.facebook.com/docs/reference/opengraph/object-type/website/
---
 layouts/_default/list.html | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/layouts/_default/list.html b/layouts/_default/list.html
index 3aa7d31..dacefe8 100644
--- a/layouts/_default/list.html
+++ b/layouts/_default/list.html
@@ -10,6 +10,10 @@
     "@type": "Person",
     "name": {{ .Site.Params.author }}
   },
+  {{ $ISO8601 := "2006-01-02T15:04:05-07:00" }}
+  {{ if not .Date.IsZero }}
+  "dateModified": {{ .Date.Format $ISO8601 }},
+  {{ end }}
   {{ with .Site.Social.GooglePlus }}
   "publisher": {{ printf "%s" . }},
   {{ end }}