Hello,
Welcome to our forum and thanks for contacting us with your question!
In order to achieve what you described, you should enable zoooming by setting
chart.zooming.type to "x" in chart config. By default, minimum zooming interval is calculated by data provided. To display hours in xAxis, you should set
minTickInterval and
minRange appropriately.
Take a look at this
demo: https://jsfiddle.net/BlackLabel/kwc71ue6/
References:
https://api.highcharts.com/gantt/chart.zooming.type
https://api.highcharts.com/gantt/xAxis.minRange
https://api.highcharts.com/gantt/xAxis.minTickInterval
Let me know if this was what you were looking for!
Best regards!