The end() method returns the current event end value or sets a new one.
DayPilot.Event.end()
DayPilot.Event.end(newEnd)The new value is applied when you call DayPilot.Scheduler.events.update().
newEnd (DayPilot.Date) - new event end value.
Call the method without parameters to read the current end value. Call it with a DayPilot.Date value to update the event object before saving it back to the control.
const oldEnd = e.end();
e.end(new DayPilot.Date("2015-10-01T00:00:00"));