Hi,
We appreciate you reaching out to us again.
Generally speaking, the default for Highchart is UTC, which is converted according to the given data, there is no literal function to exclude weekends.
Kind of like
xAxis.startOfWeek where you can choose what day the week should start with, but there is another way that might work for your goals.
You can use
xAxis.breaks to hide weekends on the chart, you need to load extra modules (
https://code.highcharts.com/modules/broken-axis.js).
Below you can find an example of how to use breaks, but you can also create a function that would insert a break in every weekend.
Live demo:
https://jsfiddle.net/BlackLabel/h9nxf3e4/
API References:
https://api.highcharts.com/gantt/xAxis.breaks
https://api.highcharts.com/gantt/xAxis.startOfWeek
Let me know if that was what you were looking for.
Best regards.