title: SetWeek negative deprecated
body: <p>I was creating a DateRange like this one in my App:</p>
  
  <pre><code>NSDateComponents *myDateComponentsStart = [[NSDateComponents alloc] init];
  [myDateComponentsStart setWeek:-2];
  
  NSDateComponents *myDateComponentsEnd = [[NSDateComponents alloc] init];
  [myDateComponentsEnd setWeek:+2];
  
  DateRange *myDateRage = [[DateRange dateRangeForToday] dateRangeByAddingStartDateComponents:myDateComponentsStart endDateComponents:myDateComponentsEnd];
  </code></pre>
  
  <p>It means a range between 2 weeks in the past and 2 weeks in the future.</p>
  
  <p>But it seems setWeek is deprecated yet for iOS 8. It propose changing it by setWeekOfMonth or setWeekOfYear.</p>
  
  <p>Since I don't care any change of month or year. What should I use now? I just want a period of 4 week with today in the middle, no worries about months or years.</p>