title: moment js is picking up the wrong timezone/offset, so the conversion from UTC to local time is incorrect
body: <p>I have read several articles, the docs at momentjs and several issues (here on stackoverflow) regarding moment and timezone handling, but I have not found the answer to how moment decides what the local UTC offset is.  I am in the America/Denver timezone and at this time of this writing, the offset is UTC-07:00.  The Windows clock is set correctly and displays the local time properly.  For a UTC timestamp of "2017-04-24 17:33:55", I expect the following code to log displayDate as "04/24 10:12:34"</p>
  
  <pre><code>dateString = "2017-04-24 17:12:34"
  console.log("dateString: " + dateString)
  utc = moment.utc(dateString)
  console.log("utc: " + utc.format())
  now = moment(utc.format())
  console.log("now: " + now.format())
  displayDate = now.format("MM/DD HH:mm:ss")
  console.log("displayDate: " + displayDate)
  </code></pre>
  
  <p>But, this is what the console shows:</p>
  
  <pre><code>dateString: 2017-04-24 17:12:34
  utc: 2017-04-24T17:12:34Z
  now: 2017-04-24T18:12:34+01:00
  displayDate: 04/24 18:12:34
  </code></pre>
  
  <p>I have no idea how it thinks I'm in a timezone with offset of UTC+01:00.  I am not using moment-timezone and have been unable to resolve why moment is picking up the wrong offset.  I noticed there is a TZ environment variable set to America/Denver, so this clearly has no effect.  How does moment determine the local offset?  Is there some sort of default setting that is messed up somewhere?  It must be something on my machine, because the same code works properly on another machine.</p>
  
  <p>In case it helps, this code lives in an AngularJS (version 1.5.8) app.</p>
  
  <p>Cheers,
  Rich</p>