title: Rails - update a model "in the future"
body: <p>We need to add a feature which allows a user to decide, before he make a change to a model, when will this change will take affect (e.g. from tomorrow at 19:43)</p>
  
  <p>The problem we've is that our model has many dependencies with many validations and there is a chance that future changes will conflict one another :</p>
  
  <ol>
  <li>Make change A to take place tomorrow (pass validation test)</li>
  <li>Make change B now - this change might have cause change A to be invalid.</li>
  </ol>
  
  <p>Is there a known solution/Gem for that issue?
  What is the best approach to tackle this?</p>
  
  <p>Thanks. </p>