title: How to get day or year number from timestamp column in postgres
body: <p>I have a Timestamp column in a table like this on postgres</p>
  
  <pre><code>CreatedAt
  
  2016-10-26 07:33:51.029
  2016-11-01 08:39:12.322
  </code></pre>
  
  <p>I need to get day like</p>
  
  <pre><code>SELECT day number or may be month number 
  FROM "MyTable";
  </code></pre>
  
  <p>expected output would be</p>
  
  <pre><code>day
  
  26
  01
  </code></pre>