title: isBetween using moment-timezone
body: <p>I am attempting to use moment-timezone to do some calculations based on an hour.</p>
  
  <pre><code>var time = moment.tz() // get the now
  var start = moment.tz('16:00:00', 'HH:mm:ss', '');
  var end = moment.tz('16:10:00', 'HH:mm:ss', '');
  
  if(time.isBetween(start, end)) {
    console.log('yep')
  }
  </code></pre>
  
  <p>but the output is always <code>undefined</code>.</p>
  
  <p>I have tried countless ways to get this to work but to no avail.</p>
  
  <pre><code>moment.tz(moment.now(), 'Europe/Lisbon').isBetween('16:00:00','17:30:00') // to get in ms
  </code></pre>
  
  <p>false</p>
  
  <pre><code>moment.tz('Europe/Lisbon').isBetween('16:00:00','17:30:00')
  </code></pre>
  
  <p>false</p>
  
  <pre><code>moment.tz(moment.tz('Europe/Lisbon').format('HH:mm:ss'), 'Europe/Lisbon').isBetween('16:00:00','17:30:00')
  </code></pre>
  
  <p>What could I be doing wrong?
  I am using time-zone because I need the actual hour of many different places.</p>
  
  <p>thanks guys</p>