c3 - JSON data with timeseries

HTML

<script src="https://rawgit.com/masayuki0812/c3/master/c3.js"></script>
<link rel="stylesheet" href="https://rawgit.com/masayuki0812/c3/master/c3.css">
<div id="chart"></div>

CSS

.xLineLable text{
  font-size: 12px;
}
.c3-grid text {
    fill: #000;
  }

JavaScript

var chart = c3.generate({
         bindto: '#chart',
    data: {
      x: 'x',
        columns: [
        ["x", "2016-01-04", "2016-01-05", "2016-01-06", "2016-01-07", "2016-01-08", "2016-01-09", "2016-01-10", "2016-01-11", "2016-01-12", "2016-01-13", "2016-01-14", "2016-01-15", "2016-01-16", "2016-01-17", "2016-01-18", "2016-01-19", "2016-01-20", "2016-01-21", "2016-01-22", "2016-01-23", "2016-01-24", "2016-01-25", "2016-01-26", "2016-01-27", "2016-01-28", "2016-01-29", "2016-01-30", "2016-01-31", "2016-02-01", "2016-02-02", "2016-02-03"],
         ["Democrates", 49.85, 49.89, 49.82, 49.51, 49.42, 49.33, 49.24, 49.64, 49.57, 49.57, 49.01, 48.67, 48.7, 48.7, 48.7, 48.63, 48.63, 48.63, 48.63, 48.63, 48.61, 48.61, 48.68, 48.76, 48.84, 48.73, 48.76, 48.79, 48.81, 49.68, 49.63],
         ["Republicans", "50.15", "50.11", "50.18", "50.49", "50.58", "50.67", "50.76", "50.36", "50.43", "50.43", "50.99", "51.33", "51.30", "51.30", "51.30", "51.37", "51.37", "51.37", "51.37", "51.37", "51.39", "51.39", "51.32", "51.24", "51.16", "51.27", "51.24", "51.21", "51.19", "50.32", "50.37"]
        ],
         colors: {
            Democrates: '#4575b4',
            Republicans: '#d73027'
        },
    },
    axis: {
        x: {
            type: 'timeseries',
            tick: {
                format: '%Y-%m-%d'
            }
        }
    },
    grid: {
     y: {
        lines: [
                {value: 50},

            ]
     },
     x: {
    lines: [
      {value: "2016-01-08", text: "Want to rorate this text in 180 degrees",
      class: "xLineLable", position: "end"}


    ]
  }
  }
});