title: Excel 365, pivot table and slicer change date format
body: <p>My employer recently rolled out the new version of Excel to us and by some reason all dates have changed from "YYYY-MM-DD" format to "DD-MMM" format.<br>
  It might sound as a small issue but it also means the slicer is now showing the dates sorted by day number, example:  </p>
  
  <pre><code>Ascending 
  1 jan
  1 feb
  2 jan
  2 feb
  </code></pre>
  
  <p>As you can understand that is not a practival way to choose dates in a slicer.<br>
  I can change from ascending to decending but that just means the higher day numbers come first.  </p>
  
  <p>I can't find any settings for this.<br>
  If I look at the clock in the lower right corner it shows YYYY-MM-DD so it's not the regional settings. I also doubble checked it with the control panel settings in windows.  </p>
  
  <p>What can I do to change this to YYYY-MM-DD?</p>
  
  <p><a href="https://i.stack.imgur.com/e18EY.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/e18EY.png" alt="enter image description here"></a></p>
  
  <hr>
  
  <h2>EDIT:</h2>
  
  <p>I have tried to change the format of the date but it make no difference.<br>
  I also tried to set a custom format but it doesn't make any difference.
  <a href="https://i.stack.imgur.com/cAUCq.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/cAUCq.png" alt="enter image description here"></a></p>
  
  <hr>
  
  <h2>EDIT2:</h2>
  
  <p>I tried to create a new pivot table and i get the following as default:<br>
  <a href="https://i.stack.imgur.com/VLYLf.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/VLYLf.png" alt="enter image description here"></a></p>
  
  <p>The months are added automatically when I add dates in the pivot table.<br>
  With or without the months there I still can't change the format.</p>
  
  <h2>Edit3:</h2>
  
  <p>I have uploaded a copy of a part of the file if anyone wants to try themselves.<br>
  It doesn't have all the columns, but it has all the rows that I have at this moment.</p>
  
  <p><a href="http://hoppvader.nu/Pics/date_format.xlsx" rel="nofollow noreferrer">http://hoppvader.nu/Pics/date_format.xlsx</a></p>