code: function offset(date) {
          // Difference to Greenwich time (GMT) in hours
          var os = Math.abs(date.getTimezoneOffset());
          var h = String(Math.floor(os/60));
          var m = String(os%60);
          h.length === 1? h = '0'+h:1;
          m.length === 1? m = '0'+m:1;
          return date.getTimezoneOffset() < 0 ? '+'+h+m : '-'+h+m;
      }
docs: Formats the TimeOffest
  Thanks to http://www.svendtofte.com/code/date_format/
  @private