title: Localization format date and number precision
body: <p>is there a way to use helper in yml file?
  I have this:</p>
  
  <p><em>en.yml</em></p>
  
  <p><code>n_buy_credits: "foo %{time}. Number %{number}."</code></p>
  
  <p>I'd like to show the %{time} parameter whit this format ("%m-%d-%Y %H:%M") and the %{number} with 2 levels of precision. Is it possible?
  Thank you</p>