[Solved]-Highcharts: yAxis duration in hours resets every 24h-Highcharts

in fact, you want to get a total time instead of datetime. in this case, you'll need to create your own label formatter that will convert milliseconds to a number of hours, minutes and seconds.

example code:

  datalabels: {
        enabled: true,
        formatter: function() {
          let s, m, h;
          s = this.y / 1000;
          h = parseint(s / 3600);
          s = s % 3600;
          m = parseint(s / 60);
          s = (s % 60).tofixed(0);
          let number = (h + ":" + m + ":" + s);

          return number;
        }
      }

api reference: https://api.highcharts.com/highcharts/series.column.datalabels.formatter

demo: https://jsfiddle.net/blacklabel/lcjewr2o/