​

​

  var ctx = document.getElementById("myChart").getContext('2d');

  var myChart = new Chart(ctx, {

    type: 'line',

    data: {

      xLabels: ["00:00", "01:00", "02:00", "03:00", "04:00", "05:00", "06:00"],

      yLabels: ['', 'On', 'Off', ' ',],

      datasets: [{

        label: 'Is boiler on?',

        steppedLine: true,

        data: ['Off', 'On', 'Off', 'On', 'Off', 'On', ' '],

      }]

    },

    options: {

      scales: {

        yAxes: [{

          type: 'category',

          position: 'left',

          display: true,

        }],

      }

    }

  });