Highcharts - show only hours and minutes in xAxis - highcharts

Question

I am trying to bring highcharts to show only hours and minues in xAxis, presently it's showing the full timestamp including the date. I am using the following code:
var chartT = new Highcharts.Chart({
chart:{ renderTo : 'chart-temperature' },
title: { text: 'Temperatur' },
series: [{
showInLegend: false,
data: IstTemp
}],
plotOptions: {
line: { animation: false,
dataLabels: { enabled: true }
},
series: { color: '#059e8a' }
},
xAxis: {
type: 'datetime',
dateTimeLabelFormats: { minute: '%H:%M' },
categories: reading_time
},
yAxis: {
title: { text: 'Temperatur (Celsius)' }
},
credits: { enabled: false }
});
Where is my mistake?

Answer 1

You can't use datetime and category axis type at the same time. As a solution you can:
Use datetime axis and preprocess your data to the format: [timestamp, y]
var IstTemp = [11.6, 12.5];
var reading_time = ["2021-02-12 14:35:52", "2021-02-12 14:38:52"];
var seriesData = IstTemp.map(function(dataEl, index){
return [new Date(reading_time[index]).getTime(), dataEl];
});
Live demo: http://jsfiddle.net/BlackLabel/7gdvzfo6/
Use categories with modified string
var IstTemp = [11.6, 12.5];
var reading_time = ["2021-02-12 14:35:52", "2021-02-12 14:38:52"];
var processedCategories = reading_time.map(function(dateStr){
return dateStr.split(' ')[1].split(':').slice(0, 2).join(':');
});
Live demo: http://jsfiddle.net/BlackLabel/2udw738c/