title: Check if a date range has a weekend
body: <p>If I have 2 dates, I know I can work out how many days, hours, minutes etc are between the 2 dates using <code>datediff</code>, e.g:</p>
  
  <pre><code>declare @start datetime;
  set @start = '2013-06-14';
  
  declare @end datetime;
  set @end = '2013-06-15';
  
  select datediff( hour, @start, @end );
  </code></pre>
  
  <p>How do I figure out if the date range includes a weekend?</p>
  
  <p>The reason why I want to know if the date range includes a weekend is because I want to subtract the weekend from the day or hour count.  i.e. if the start day is Friday, and the end date is Monday, I should only get 1 days or 24 hours.</p>
  
  <p>Datepart 1 = Sunday, and datepart 7 = Saturday on my server.</p>