title: Spec is failing on the same hour
body: <p>In my app I have few specs that depend on distracting some dates:</p>
  
  <pre><code>survey_instance.created_at + 1.day
  </code></pre>
  
  <p>then I check if collection of survey_instances have proper size. But this specs fails always at 3 a.m. How can I distract dates to avoid that problem?</p>