title: Converting UTC DateTime to EST DateTime with correct offset
body: <p>My app gets a DateTime object in UTC and needs to output as a string it in EST format.  I've tried the following code, but when I get the output the offset still shows as +00:00 instead of -05:00</p>
  
  <pre><code>static void Main(string[] args)
      {
          var currentDate = DateTime.Now.ToUniversalTime();
          var convertedTime = ConvertUtcToEasternStandard(currentDate);
  
          Console.WriteLine(currentDate.ToString("yyyy-MM-ddTHH:mm:sszzz"));
          Console.WriteLine(convertedTime.ToString("yyyy-MM-ddTHH:mm:sszzz"));
      }
  
  private static DateTime ConvertUtcToEasternStandard(DateTime dateTime)
      {
          var easternZone = TimeZoneInfo.FindSystemTimeZoneById("Eastern Standard Time");
          return TimeZoneInfo.ConvertTimeFromUtc(dateTime, easternZone);
      }
  </code></pre>
  
  <p>This outputs:</p>
  
  <pre><code>2016-11-18T06:56:14+00:00
  2016-11-18T01:56:14+00:00
  </code></pre>
  
  <p>So the time is being shifted correctly, but the offset stays at +00:00 when I want it to be -05:00.  Any idea how I can get a DateTime object with the correct offset when output with the above format string?</p>