DC References Two

<!DOCTYPE html>
<meta charset='utf-8'>
<style>
body {
  font: 10px sans-serif;
  shape-rendering: crispEdges;
}

.day {
  fill: #fff;
  stroke: #ccc;
}

.month {
  fill: none;
  stroke: #000;
  stroke-width: 2px;
}

.RdYlGn .q0-11{fill:rgb(165,0,38)}
.RdYlGn .q1-11{fill:rgb(215,48,39)}
.RdYlGn .q2-11{fill:rgb(244,109,67)}
.RdYlGn .q3-11{fill:rgb(253,174,97)}
.RdYlGn .q4-11{fill:rgb(254,224,139)}
.RdYlGn .q5-11{fill:rgb(255,255,191)}
.RdYlGn .q6-11{fill:rgb(217,239,139)}
.RdYlGn .q7-11{fill:rgb(166,217,106)}
.RdYlGn .q8-11{fill:rgb(102,189,99)}
.RdYlGn .q9-11{fill:rgb(26,152,80)}
.RdYlGn .q10-11{fill:rgb(0,104,55)}
</style>
<body>
<script src='https://d3js.org/d3.v3.min.js'></script>
<script>

var width = 960,
    height = 136,
    cellSize = 17; // cell size

var day = d3.time.format('%w'),
    week = d3.time.format('%U'),
    format = d3.time.format('%Y-%m-%d');

var color = d3.scale.quantile()
    .range(d3.range(11).map(function(d) { return 'q' + d + '-11'; }));

var svg = d3.select('body').selectAll('svg')
    .data(d3.range(1970, 2013))
  .enter().append('svg')
    .attr('width', width)
    .attr('height', height)
    .attr('class', 'RdYlGn')
  .append('g')
    .attr('transform', 'translate(' + ((width - cellSize * 53) / 2) + ',' + (height - cellSize * 7 - 1) + ')');

svg.append('text')
    .attr('transform', 'translate(-6,' + cellSize * 3.5 + ')rotate(-90)')
    .style('text-anchor', 'middle')
    .text(function(d) { return d; });

rect.append('title')
    .text(function(d) { return d; });

svg.selectAll('.month')
    .data(function(d) { return d3.time.months(new Date(d, 0, 1), new Date(d + 1, 0, 1)); })
  .enter().append('path')
    .attr('class', 'month')
    .attr('d', monthPath);

d3.json('dates_compressed.json', function(error, data) {
  color.domain(d3.values(data));
  rect.filter(function(d) { return d in data; })
      .attr('class', function(d) { return 'day ' + color(data[d]); })
    .select('title')
      .text(function(d) { return d + ': ' + data[d] + ' times referenced'; });
});

function monthPath(t0) {
  var t1 = new Date(t0.getFullYear(), t0.getMonth() + 1, 0),
      d0 = +day(t0), w0 = +week(t0),
      d1 = +day(t1), w1 = +week(t1);
  return 'M' + (w0 + 1) * cellSize + ',' + d0 * cellSize
      + 'H' + w0 * cellSize + 'V' + 7 * cellSize
      + 'H' + w1 * cellSize + 'V' + (d1 + 1) * cellSize
      + 'H' + (w1 + 1) * cellSize + 'V' + 0
      + 'H' + (w0 + 1) * cellSize + 'Z';
}

d3.select(self.frameElement).style('height', '2910px');
</script>

Modified http://d3js.org/d3.v3.min.js to a secure url

https://d3js.org/d3.v3.min.js