title: Sheets: how to return NULL value in IF formula that looks up date value
body: <p>I'm pretty sure this is a simple formula. I'm in Google Sheets and I want to find the latest date for a value in one sheet based on the value found in another sheet, or return a null value (blank) if there i no match. Here's what I have now: </p>
  
  <pre><code>=arrayformula(Max(IF(B285='2014 Donations Log'!F:F,'2014 Donations Log'!A:A)))
  </code></pre>
  
  <p>BUT. I want the cell to be BLANK if there is no corresponding value in 2014 Donations Log. If I add anything to the IF test, (such as ,"") then it returns a bogus date value that is misleading.</p>
  
  <p>The column is formatted for date.</p>
  
  <p>I need this as a formula.</p>
  
  <p>Any ideas?</p>