title: How to get time interval since unix epoch reference date with precision down to the second?
body: <p>We have a simple multiplayer table game that uses no networking connection. It has a pulsing animation which we want to play in sync with all other devices.</p>
  
  <p>To do this I looked at NSDate -timeIntervalSinceReferenceDate to calculate a delay. Assuming all devices deliver the exact same value at the exact same time. But we found there is a difference of several seconds so this value is not very precise. Each device is a bit off from the true, correct time.</p>
  
  <p>Is there an alternative, more precise way to get the time interval since reference date?</p>