title: How can I compare (like isBefore) date with diferentes zones
body: <p>How can I compare two dates using moment-timezone, I'm trying:</p>
  
  <pre><code>const mtz = require ('moment-timezone');
  
  let dt = new Date ();
  let tokyo = mtz(dt).tz("Asia/Tokyo"); // JST +12
  let new_york = mtz(dt).tz("America/New_York"); // MDT -4
  
  console.log (new_york.isBefore (tokyo)); // returns false
  console.log (tokyo.isBefore (new_york)); // returns false too
  </code></pre>
  
  <p>Why both of then returns false?
  Tks</p>