title: epoch time and MySQL query
body: <p>I have a table like this:</p>
  
  <pre><code>id   | date
  ---- | -----------
  1    | 1319043263
  2    | 1319043578
  </code></pre>
  
  <p>which date field format is in epoch. I have to group every row that belongs to same day and show them in a separate group. How can I do that in MySQL?</p>
  
  <p>Thanks.</p>