Highchart ,display time in regular interval - highcharts

Question

Im trying to display a simple graph with x axis as time and y axis as points.
But, the time values seems to be off a little bit. The distance between 2017-10-06 &&= 2017-10-07 is smaller than 2017-10-10 & 2017-10-11 even though they are at same 1 day gap. How do I fix this?
Here is my code
function generatepointgraph(data) {
// Create the chart
Highcharts.setOptions({
global: {
useUTC: true
}
});
Highcharts.chart('points-container', {
chart: {
type: 'spline'
},
credits: {
enabled: false
},
xAxis: {
type: 'datetime',
dateTimeLabelFormats: {
second: '%Y-%m-%d<br/>%H:%M:%S',
minute: '%Y-%m-%d<br/>%H:%M',
hour: '%Y-%m-%d<br/>%H:%M',
day: '%Y-%m-%d',
week: '%Y-%m-%d',
month: '%Y-%m',
year: '%Y'
}
},
yAxis: {
title: {
text: 'Weighted pts'
}
},
scrollbar: {
showFull: true
},
rangeSelector: {
enabled: false
},
title: {
text: 'Pts vs time',
},
series: [{
name: 'Points',
data: data,
step: true,
tooltip: {
valueDecimals: 2
}
}]
});
}