title: How do you find the same weekday last year in SQL?
body: <p>Often in sales reports and so on you need to compare this day to the same day last year, but based on the same "weekday", not "day of month".</p>
  
  <p>So for example, today is the 20th June 2013 and a Thursday.  I want to see sales for today, versus the same THURSDAY last year (21st June 2012, as opposed to 20th June 2012 which was a Wednesday).</p>
  
  <p>How can this be done in T-SQL?</p>