title: How do I set the collection for the years in a simple-form field with a date format?
body: <p>I'm using simple-form, but I'm having a hard time to show the date_of_birth correctly. This is probably because of a combination of limited documentation on simple-form and more so the fact that I'm a rooky.</p>
  
  <p>Anyways, I'm trying to create a collection of the years people can choose from for their birthdate. </p>
  
  <p>date_of_birth is an attribute of the user in the DATE form, which requires input of a year, month and day. Now I tried to change the collection for the years as below, but this removes the input fields for day and month:</p>
  
  <pre><code>= simple_form_for(@user, :html =&gt; { :class =&gt; 'form-horizontal' }) do |f|
    ...
    = f.input :date_of_birth, :collection =&gt; 1910..2010
  </code></pre>
  
  <p>I'm using Simple-form on Ruby on Rails with HAML. So question is: What is the correct way to just define the collection for the years, keeping the defaults for the input of day and month?</p>