Highcharts x axis formatting options - json

Question

I am a beginner for highcharts. I was trying something and got stuck. My x axis has values repeated multiple times. Tooltip values should contain date and time as shown. but the thing i want to change is the x axis values. same value must be shown only once and not repeated everywhere where there is data.
X axis format must be DD-MMM and tooltip should be DD-MM-YY HH am/pm .
is this possible?
Here is my trial code
http://jsfiddle.net/j6oqcgp2/
Highcharts.chart('container', {
chart: {
type: 'spline'
},
title: {
text: 'Snow depth at Vikjafjellet, Norway'
},
subtitle: {
text: 'Irregular time data in Highcharts JS'
},
xAxis: {
categories:['01-Feb-17 12 AM','01-Feb-17 01 AM','01-Feb-17 02 AM','02-Feb-17 04 AM','02-Feb-17 05 AM','02-Feb-17 06 AM','02-Feb-17 07 AM'],
labels: {
formatter: function () {
y=(this.value).substring(1,6);
return y;
}
}
},
yAxis: {
title: {
text: 'Snow depth (m)'
},
min: 0
},
tooltip: {
formatter: function () {
y=(this.x).substring(0,15);
return y;
},
shared:false
},
plotOptions: {
spline: {
marker: {
enabled: true
}
}
},
series: [{
name: 'Winter 2012-2013',
// Define the data points. All series have a dummy year
// of 1970/71 in order to be compared on the same x axis. Note
// that in JavaScript, months start at 0 for January, 1 for February etc.
data: [5,10,19,10,4,6,8]
}]
});
and this is how i want it to be

Answer 1

If your x-axis categories are going to be a predictable set of values (for example, four readings on each day), then you simply can add the tickInterval attribute to show a new axis label on when the day changes (see http://api.highcharts.com/highcharts/xAxis.tickInterval).
So, if you had four readings per day, you would add tickInterval: 4 to your x-axis options. This would show an axis label at every fourth reading, or, in this example, once per day.
If, however, your x-axis categories are not predictable (for example, any number of readings per day), you may want to look at this Highcharts demo, which shows a chart with irregular time periods: http://www.highcharts.com/demo/spline-irregular-time. In this demo, you'll see regular, non-repeating axis labels for whatever unit you're measuring (hours, days, etc.) and the data being plotted as frequently as it's recorded in the data.
I hope these examples and resources are helpful for you.