Version is 8.1.1947 It was reproduced when you register the event.
I setting a fixed value when generate a daypilot. Do I mistake the use of plugin?
Sorry for the delay! This turned out to be a bug of the .update() method. It should be fixed now in the latest sandbox build (8.1.1981):
http://javascript.daypilot.org/sandbox/
Let me know if there is any problem.