title: Get today's date in Jekyll with Liquid markup
body: <p>This (should) be easy, I think, but I'm unable to get today's date to show in a Jekyll page using Liquid markup. According to <a href="https://github.com/Shopify/liquid/wiki/Liquid-for-Designers" rel="noreferrer">the documentation</a>, I should be able to do this to get this date's year:</p>
  
  <pre><code>{{ 'now' | date: "%Y" }}
  </code></pre>
  
  <p>But all that gets rendered is the string <code>now</code>, not any formatted date. What am I doing wrong?</p>