title: How do I get the correspondent day of the quarter from a date field?
body: <p>I have a dataset where the dates are between <code>5/1/2016</code> and <code>5/21/2016</code>. I would like to create a new variable <code>day_quarter</code> which will be the correspondent day of the quarter.
  For example: </p>
  
  <p>The first day in the Q2 is April 1st so, May 15th would be 45/91 for example.</p>
  
  <p>Any ideas?</p>