title: Stop Excel from updating formula after a criteria is matched
body: <p>Is there a way to stop a formula from updating after a certain criteria is matched?</p>
  
  <p>For example:</p>
  
  <pre><code>A1 = 1
  B1 = '=A1*2'
  </code></pre>
  
  <p>Lets say this is the current one. Tomorrow data will change</p>
  
  <pre><code>A1 = 2
  B1 = '=A1*2'
  </code></pre>
  
  <p>I need to be able to fix the value of cell B1 at 2 (1*2) and not have it update to 4 (2*2). The trigger should be the date.</p>
  
  <p>The values in A1 will switch dynamically; I can't stop that, I just need the ability to stop other cells from updating after a date is matched.</p>