title: Ruby on Rails: strftime() in Active Admin form
body: <p>this is how in front-end current date gets saved in database automatically(without datepickers n stuff):</p>
  
  <pre><code>&lt;% for order in @orders %&gt;
  &lt;%= order.updated_at.strftime("%Y-%m-%d %I:%M") %&gt;
  </code></pre>
  
  <p>That works, data in database: 2013-05-03 21:32:59.847009</p>
  
  <p>But the problem is that for back-end I'm using Active Admin, and I'm making form, so orders can be edited.
  But the thing is I don't really understand how to apply the same strftime function there, I thought it would be something like this:</p>
  
  <pre><code>f.input :updated_at, :date.strftime("%Y-%m-%d %I:%M")
  </code></pre>
  
  <p>But it's not correct. Getting error:</p>
  
  <pre><code>undefined method `strftime' for :date:Symbol
  </code></pre>
  
  <p>Does anyone know of a solution on how to correctly implement strftime in that line?</p>