title: EventKit: reminders dueDateComponents vs Alarm
body: <p>I want to create a reminder from my app, so I've created a reminder (EKReminder) and set up an alarm:</p>
  
  <pre><code>NSTimeInterval timeInterval = 100000;
  NSDate *alarmDate = [NSDate dateWithTimeIntervalSinceNow:timeInterval];
  EKAlarm *alarm = [EKAlarm alarmWithAbsoluteDate:alarmDate];
  [reminder setAlarms:@[alarm]];
  </code></pre>
  
  <p>but I see there is also a dueDateComponents property on EKReminder. What is the difference between setting an alarm and the dueDateComponents?</p>
  
  <p>Also there there is a method to create an alarm: <code>alarmWithRelativeOffset:(NSTimeInterval)offset</code> but the docs say the offset argument can be negative, how is it possible to have an alarm in the past?</p>