title: How can I record the date (before beeing modified) in SharePoint?
body: <p>This is my first post, I am Dani.</p>
  
  <p>I would like to know how to record a date in another column when this one is modified in SharePoint.</p>
  
  <p>I have a tasks list with some columns, one of them is "Deadline Date" and another one is "Previous Deadline Date", I would like to record the "Deadline Date" when is modified in "Previous Deadline Date". (Not the Last date Modified)</p>
  
  <p>I think this has to be done with a Calculated Column but I do not know how to build it, the logic of the formula should be something like that:</p>
  
  <p><code> =IF([Next Deadline Date] "is modified", then Record [Next Deadline Date])</code></p>
  
  <p>Any help, explication or  Link to understand how to calculated fields works in this case is very welcome.</p>
  
  <p>I would like to avoid Code due permissions but I accept suggestions too.</p>
  
  <p>Thanks very much!</p>