end() end(newEnd)
The new value is applied when you call dp.events.update(e) [e.g. DayPilot.Scheduler.events.update()].
If called without a parameter it returns an event end (DayPilot.Date).
var oldEnd = e.end();
e.end(new DayPilot.Date('2015-10-01T00:00:00'));