Jekyll Age

Jekyll Age provides an age tag for jekyll/liquid which displays the current age in years.

Add gem "jekyll-age" to your Gemfile. For example:

 group :jekyll_plugins do
   gem "another-jekyll-plugin"
   gem "jekyll-age"
 end

Now run bundle install to install all plugins in the Gemfile.

Alternatively, add the plugin to your _config.yml file in an array with the key plugins and run gem install jekyll-age.

plugins:
  - another-jekyll-plugin
  - jekyll-age

In your markdown file, simply use the template tag age with a date ({% age 'YYYY-MM-DD' %}) and the plugin will output the appropriate age in years.

If you write the following markdown:

{% age '1989-12-17' %} years

The plugin will print (given that the current date is before 2019-12-17):

29 years

MIT