title: Rails set default DateTime to now
body: <p>In my app I have teams and each team has a game time every week. I want the game times to be set to 'now' as a default. My table is set up like so</p>
  <pre><code>create_table &quot;teams&quot;, force: true do |t|
    t.datetime &quot;wk1_time&quot;
  end
  </code></pre>
  <p>I created a migration and it looks like this:</p>
  <pre><code>class ChangeDateTimeDefault &lt; ActiveRecord::Migration
    def change
      change_column :teams, :wk1_time, :default =&gt; DateTime.now
    end
  end
  </code></pre>
  <p>When I run rake db:migrate I get an error. Is my syntax wrong or am I missing something else?</p>