Chartjs timeaxis problem with #4658

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.20.1/moment.min.js"></script>
<script src="https://rawgit.com/nagix/nagix.github.io/chartjs/Chart.4658.js"></script>
<canvas id="myChart" width="400" height="300"></canvas>
<hr>
<br>
<br>
<h2>
Plotted Daily with offset = true
</h2>
<canvas id="myChart_daily" width="400" height="300"></canvas>

JavaScript

const CHART_COLORS = ['rgba(58, 186, 50, 1)', 'rgba(16, 208, 231, 1)']

function generate_ds(keys, data, colors) {
  let result = [];
  for (let idx = 0; idx < keys.length; idx++) {
    let color = colors[idx];
    let obj = {
      label: keys[idx],
      backgroundColor: color,
      borderColor: color,
      data: data[idx],
      fill: false,
      radius: 30
    }
    result.push(obj);
  }
  return result
}

function mapProp(obj, property) {
    return obj.map(_ => _[property]);
}


let url = 'https://api.myjson.com/bins/9evr5'
$.ajax({
  type: 'GET',
  url: url,
  contentType: "application/json",
  dataType: 'json',
  success: function(data) {
    var ctx = document.getElementById("myChart").getContext("2d");
    var ctx_daily = document.getElementById("myChart_daily").getContext("2d");


    let result_by_month = data.map(item => ({
      date: moment(item['date']).format('MMM, YYYY'),
      impact: item.impact,
      opportunity: item.opportunity
    }));

    let rbm_obj = {};
    result_by_month.forEach(el => {
      rbm_obj[el.date] = rbm_obj[el.date] || {};
      rbm_obj[el.date].impact = rbm_obj[el.date].impact || [];
      rbm_obj[el.date].opportunity = rbm_obj[el.date].opportunity || [];

      rbm_obj[el.date].impact.push(el.impact);
      rbm_obj[el.date].opportunity.push(el.opportunity);
    })

    let impact_daily = [];
    let opp_daily = [];
    for (let obj of data) {
      impact_daily.push(obj['impact']);
      opp_daily.push(obj['opportunity']);
    }
    

    let impact = [];
    let opp = [];
    for (let obj of Object.values(rbm_obj)) {
      impact.push(obj.impact.reduce((acc, curr) => acc + curr))
      opp.push(obj.opportunity.reduce((acc, curr) => acc + curr))
    }

    let labels = ['Label A', 'Label B']
    let ds = generate_ds(labels, [impact_daily, opp_daily], CHART_COLORS)
    let ds1 = generate_ds(labels, [impact, opp], CHART_COLORS);


    let chart_data_monthly = {
      labels: Object.keys(rbm_obj),
      datasets: ds1
...