Using DateTime value on Y Axis - CanvasJS JavaScript Charts

Using DateTime value on Y Axis - CanvasJS JavaScript Charts (Time(X axis) and day(Y-axis))

HTML

<script src="https://canvasjs.com/assets/script/canvasjs.min.js"></script>
<br/><!-- Just so that JSFiddle's Result label doesn't overlap the Chart -->

<div id="chartContainer" style="height: 360px; width: 100%;"></div>

JavaScript

var z;
                var chart = new CanvasJS.Chart("chartContainer",
                {
                    axisX: {
                    },
                    axisY: {
             
                        interval: (1 * 60 * 60 * 1000 * 24),
                        labelFormatter: function(e){
                            return CanvasJS.formatDate(e.value, "DD MMM YYYY");
                        },
                        crosshair: {
                            enabled: true,
                            labelFormatter: function(e){
                            z= e.value;
                            console.log(z);
                            return CanvasJS.formatDate(e.value, "DD MMM YYYY");
                            }
                        },
                    },
                        //suffix : " hour"               
                            toolTip:{
                            contentFormatter: function(e){
                                return "Elapsed Time: " + ((z.toFixed()-e.entries[0].dataPoint.y[0])/(e.entries[0].dataPoint.y[1]-e.entries[0].dataPoint.y[0])).toFixed(2)
               	+"| End Period: " +  CanvasJS.formatDate(e.entries[0].dataPoint.y[1], "DD MMM YYYY");   
                            }},
                    data: [
                    {
                        type: "rangeBar",
                        dataPoints: [
                        ]
                    }
                    ]                      
                });
                chart.render();