Set Last Modified Date Automatically


I’ve wanted to see when a blog post was last updated. My current Hugo theme doesn’t offer support for this. Luckily I found this blog post and modified it to my needs.

Changes to config.yaml

Since I don’t have everywhere in the frontmatter a lastmod value, I need to rely on the git timestamp. I have to modify the config.yaml so that Hugo can use this information. In case I’ve added the lastmod manually, it should override the information from git:

enableGitInfo: true

  lastmod: ['lastmod', ':git', 'date', 'publishDate']

Modify the theme

Existing files from a theme can be overridden. You’ll need to copy the existing file to the same place in your layouts folder. I’ve added these changes to my details.html:

{{ if or (not .Date.IsZero) (.Site.Params.article.readingTime) }}
    <footer class="article-time">
        {{ if not .Date.IsZero }}
                {{ partial "helper/icon" "date" }}
                <time class="article-time--published">
                    {{- .Date.Format (or .Site.Params.dateFormat.published "Jan 02, 2006") -}}
        {{ end }}

        <!-- Created Date -->
        {{- $pubdate := .PublishDate.Format "Jan 02, 2006" }}
        <!-- Last Updated Date -->
        {{- if .Lastmod }}
            {{- $lastmod := .Lastmod.Format "Jan 02, 2006" }}
                {{- if ne $lastmod $pubdate }}
                    Last modified:
                    <time class="article-time--updated" datetime="{{ .Lastmod }}" title="{{ .Lastmod }}">
                        {{ $lastmod }}
            {{- end }}
        {{- end }}

        {{ if .Site.Params.article.readingTime }}
                {{ partial "helper/icon" "clock" }}
                <time class="article-time--reading">
                    {{ T "article.readingTime" .ReadingTime }}
        {{ end }}


Now you’ll see in lot of my posts a “Last modified” next to the published date. I’ve updated almost all my posts, as they were recently modified to be compatible with Hugo.

Last updated on Jan 24, 2022 22:19 +0100