title: How to group by week of the year dates or day dates that start on Sundays in oracle 10?
body: <p>Given a table:</p>
  
  <p>day_date (form of yyyy-mm-dd)
    column2
    column3</p>
  
  <p>I want to group the data by weeks, and the start of each week goes from Sunday to Saturday, but I want to display the day_date.</p>
  
  <p>I have looked around all over, and I'm rusty on my SQL.</p>
  
  <p>Thanks!</p>