title: Is the time synchronized across multiple dynos on Heroku?
body: <p>Is there any article on how synchronized are the times across multiple dynos in heroku, and how reliable they are?</p>
  
  <p>I am running a node.js application on Heroku and need to know if the time that I get using <code>Date.now()</code> or <code>new Date()</code> is synchronized across multiple dynos?</p>
  
  <ol>
  <li>Using cluster module, it seems that all the processes running on the same dyno have the same time. Do they use the local machine time or a clock server?</li>
  <li>I tested with two dynos in the same app to print the timestamp as soon as they start and they seemed to have the same time. Is this reliable? </li>
  <li>I did not test with dynos on different apps. Are they likely to have the same time or in a reliable difference range?</li>
  </ol>
  
  <p>By the same time, i mean the time differences were less than 1000ms, which can be due to slightly difference process staring times. </p>