TimeSlider - Event Handler

[RRicardo]

I'm programming an app with data from the ArcGIS Indoors Information Model. I have a time-aware feature layer (Events) with point features. My second feature layer (Units) (non time-aware) includes polygon features. The Units layer is under the Events layer. Both layers are connect by IDs and the geometries intersect. The timeslider widget works and shows the events correctly. 

Now I have an idea that I would like to implement:

When using the timeslider, I would like to symbolize the associated units differently while an event takes place. I searched for events for the timeslider in the API reference, but couldn't find any: https://developers.arcgis.com/javascript/latest/api-reference/esri-widgets-TimeSlider.html#on
I suspect there are no events for the widget.

Does someone has an idea how I can still implement my idea?

Best, 

Ricardo

[KenBuja · Accepted solution]

In JS 4.x, instead of listening for events, you have to watch for changes in a property of a widget. You can watch the timeExtent property to make your symbology changes.

[RRicardo]

Thank you!