title: Find date ranges between large gaps and ignore smaller gaps
body: <p>I have a column of a mostly continous unique dates in ascending order. Although the dates are mostly continuos, there are some gaps in the dates of less than 3 days, others have more than 3 days.</p>
  
  <p>I need to create a table where each record has a start date and an end date of the range that includes a gap of 3 days or less. But a new record has to be generated if the gap is longer than 3 days.</p>
  
  <p>so if dates are:</p>
  
  <pre><code>    1/2/2012
      1/3/2012
      1/4/2012
      1/15/2012
      1/16/2012
      1/18/2012
      1/19/2012
  </code></pre>
  
  <p>I need:</p>
  
  <pre><code>    1/2/2012      1/4/2012
      1/15/2012     1/19/2012
  </code></pre>