title: What is a good way to find gaps in a set of datespans?
body: <p>What is a way to find gaps in a set of date spans?</p>
  
  <p>For example, I have these date spans:  </p>
  
  <pre><code>1/ 1/11 - 1/10/11  
  1/13/11 - 1/15/11  
  1/20/11 - 1/30/11
  </code></pre>
  
  <p>Then I have a start and end date of 1/7/11 and 1/14/11.</p>
  
  <p>I want to be able to tell that between 1/10/11 and 1/13/11 there is a gap so the start and end date is not possible.  Or I want to return only the datespans up to the first gap encountered.</p>
  
  <p>If this can be done in SQL server that would be good.</p>
  
  <p>I was thinking to go through each date to find out if it lands in a datespan... if it does not then there's a gap on that day.</p>