title: How to compare NSDate to check if dates are within the same week
body: <p>I have two NSDates. How can I compare them to find out if the dates are within the same week. </p>
  
  <p>I have a system that currently checks if two dates are within the same day and the code for this is below:</p>
  
  <pre><code>if calan.compareDate(datee, toDate: now, toUnitGranularity: .CalendarUnitDay) == .OrderedSame {
      transactionsToday.addObject(transaction)
  }else{
      println("No transactions today")
  }
  </code></pre>
  
  <p>Which UnitGranularity would I use to check if the two dates share the same week?</p>