The onBeforeEventRender event is fired before the JavaScript Monthly Calendar renders an event. It lets you customize the event properties dynamically.
DayPilot.Month.onBeforeEventRender(args)args.control - DayPilot.Month reference; available since 2023.3.5716
args.data - raw event data object (shallow copy)
dp.onBeforeEventRender = function(args) {
args.data.cssClass = "test";
args.data.html = args.data.text + ":";
};