title: Query timestamps in Google Sheets looking for specific date but ignoring the time
body: <p>I have a range of data with a timestamp in the first column. I want the average of a particular column (AF) for a specific date, regardless of what time the timestamp has.</p>
  
  <p>The formula I'm currently working on looks something like this but it returns an empty result set although I can see the data is present.</p>
  
  <pre><code>=query(ImportedData1!A1:AF, "Select avg(AF) where A = date '2019-04-08' label avg(AF) '' ", 0)
  </code></pre>
  
  <p>What am I doing wrong, please?</p>