first tick odd

HTML

<script src="http://chartjs.org/dist/master/Chart.bundle.min.js"></script>
<canvas id="myChart" width="400" height="200"></canvas>

JavaScript

var canvas = document.getElementById('myChart');
var config = {
  "type": "line",
  "data": {
    "datasets": [{
      "type": "line",
      "label": ["", "ModulationTempDesired", ""],
      "backgroundColor": "#90a4ae",
      "borderColor": "#90a4ae",
      "yAxisID": "axis3",
      "xAxisID": "axis-time",
      "borderWidth": 1,
      "fill": false,
      "pointRadius": 0,
      "steppedLine": "before",
      "data": [{
        "x": 1498863475647,
        "y": 40
      }, {
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        "y": 40
      }, {
        "x": 1498870443885,
        "y": 40
      }, {
        "x": 1498874166069,
        "y": 40
      }, {
        "x": 1498877769253,
        "y": 40
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        "y": 40
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        "y": 36.03
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        "y": 50.964
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        "y": 52.9
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      }, {
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        "y": 45.963
      }, {
        "x": 1498906598807,
        "y": 40.8
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      }, {
        "x": 1498924732834,
        "y": 51.422
      }, {
        "x": 1498928336499,
        "y": 40.6
      }, {
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      }, {
        "x": 1498935363568,
        "y": 40.6
      }, {
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      }, {
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        "y": 30.332
      }, {
        "x": 1498960647028,
     ...