title: What is the Android/Java equivalent of the iOS call [NSDate timeIntervalSinceNow]?
body: <p>Here is some sample code from iOS:</p>
  
  <pre><code>NSDate *startDateX = [NSDate date];
  
  // Do a bunch of stuff
  
  NSLog(@"Time difference: %f", -[startDateX timeIntervalSinceNow]);
  </code></pre>
  
  <p>The output looks like this:</p>
  
  <pre><code>Time difference: 15.009682
  </code></pre>
  
  <p>What is the equivalent way to do this in Android/Java?</p>