title: How to get start day timestamp and end day timestamp from value
body: <p>For example I have one column <code>TIMESTAMP WITH TIME ZONE</code> with value <code>'2017-07-09 19:43:54.418544'</code>
  How to get from this value something like this :</p>
  
  <pre><code>2017-07-09 00:00:00 as start_day,
  2017-07-09 23:59:59 as end_day
  </code></pre>