Highcharts currently does not support setting different timezones. One workaround was to send data in local time and tell Highcharts to treat these timestamps as UTC timezones. Another solution is to send the data in UTC timezone and use a different xAxis formatter to adjust the timezone difference. This is just a starting point for others facin…

xAxis-formatter-localtime

       xAxis: {
           type: 'datetime',
           labels: {
               align: 'center',
               y: 15,
               formatter: function(){
                  var datetime = moment.utc(this.value);

                  var utcOffset = 0;
                  // utcOffset should be set globally to whatever timezone you want to show
                  if (self.options.utcOffset) {
                      utcOffset = self.options.utcOffset * 60;
                  }
                   
                  if (utcOffset > 0) {
                    datetime = datetime.add('minutes', Math.abs(utcOffset));
                  }
                  else {
                    datetime = datetime.subtract('minutes', utcOffset);
                  }

                  return datetime.format('H:mm');
               }
           },
         plotLines: []
       },