title: strftime('%-d') fails on heroku web dynos
body: <p>On heroku, rails rendering on my web dynos gives me</p>
  
  <pre><code>Time.now.strftime('%a, %b %-d')
  =&gt; "Wed, Mar -d"
  </code></pre>
  
  <p>Running heroku console gives me the expected behavior</p>
  
  <pre><code>Time.now.strftime('%a, %b %-d')
  =&gt; "Wed, Mar 13"
  </code></pre>
  
  <p>I have a monkeypatch that fixes it, but I'd be interested if anyone has a cleaner solution</p>