Q:

How do I detect a zoom event in highcharts?

Is it possible to detect a zoom event in Highcharts? My use case is that I have some state external to the chart, and when the user zooms in on part of it I want to detect what the new time range on the x-axis is and update the corresponding external state.

A:

Have you tried going through the Highcharts API?
You may want to look @ 
xAxis.events.setExtremes
And/Or
chart.events.selection

