title: How to determine the week of year starting on sunday using Python?
body: <p>I need to get the week of year starting on sunday. The default ISO Week starts on monday, but my requirement is to get the sunday as the start of week.</p>
  
  <p>for instance <strong>2019-01-06</strong> is a <strong>sunday</strong> and it should be week 2.</p>
  
  <p>i did try </p>
  
  <pre><code>t1.strftime("%U")
  </code></pre>
  
  <p>but the problem is it retuns 0 for all days in a new year preceding the first Sunday and starts the week count from first sunday of the year.</p>
  
  <p>Thanks for the help in advance.</p>