title: How to determine if a date range occurs any time within another date range?
body: <p>I have an Event table that specifies a date range with <code>start_date</code> and <code>end_date</code> fields.  I have another date range, specified in code, that defines the current week as 'week_start' and 'week_end'.</p>
  
  <p>I'd like to query all Events for the week.  The cases seem to be:</p>
  
  <ul>
  <li>Event begins and ends within the week</li>
  <li>Event begins before the week, but ends within the week</li>
  <li>Event begins within the week, but ends after the week</li>
  <li>Event begins before the week and also ends after the week</li>
  <li><em>Events that neither reside within, nor overlap the week at all are ignored</em></li>
  </ul>
  
  <p>I'm attempting to come up with a query that can handle all these cases.  So far I've only been able to get cases that handle the week overlaps, or events that are fully internal; Essentially, too many records, or none at all.</p>