Hello davidchuco!
We appreciate you reaching out to us!
First of all, in your demo, there is an error 15 in the console, which means that your data is not sorted (
https://assets.highcharts.com/errors/15/) I have sorted it by days and as you can see the error is gone.
Your xAxis labels are not centred on a group of points, because the dates (x-value) of these points are not the same as from ticks. To achieve the look, which you requested you have some ways.
In the first way, you can use the Highstock module and
dataGrouping feature, which is set to one day - you can check it in the first demo below.
Another approach could be using
tickPositions array to place ticks in desired positions (same as x-values of points), then just add a
labels.formatter to show days as labels. You can see an example in the second demo below.
Demo with dataGrouping: https://jsfiddle.net/BlackLabel/qtfc48p9/
Demo with tickPositions: https://jsfiddle.net/BlackLabel/5qrLh3aj/
API Reference: https://api.highcharts.com/highstock/se ... taGrouping
https://api.highcharts.com/highcharts/x ... kPositions
https://api.highcharts.com/highcharts/x ... .formatter
Let me know if you have any further questions.
Kind regards!