Gantt APITemplatesmarker_classOn this pagemarker_class Description Specifies the CSS class that will be applied to markers marker_class: (marker: any) => void;Parameters marker - (required) object - the marker's configuration object Examplevar showAdvancedMarkers;gantt.templates.marker_class = function(marker){ if (showAdvancedMarkers) { return "advanced_marker"; } return "hidden";}Related Guides Adding Vertical Markers