title: How to auto update a cell to the current date if another cell´s value got changed
body: <p>I would like to do the following: Whenever anything in cell A2, A3, A4 is changed, the corresponding date in cell B2, B3, B4 should be updated to the current date. If nothing is done in A2, A3, A4, the dates in B2, B3, B4 should not be updated.</p>
  
  <p>Any ideas how to accomplish that? </p>
  
  <p>For reference pls. see the screenshot 
  <img src="https://i.stack.imgur.com/LTp0K.jpg" alt="enter image description here"></p>