That doesn't fix it unfortunately.
I think the root of the issue is back when for some reason November 5th was listed twice.. maybe 2/3 service packs ago. Now it's only listed once but it still changes the size of the appointment.
You can see how it works in your javascript demo.
http://js.syncfusion.com/demos/web/dashboard/hospitalmanagement/default.html
Go to Month View.
Go to November
Add an appointment.
Move it to November 5th 2017! (if you do it in 2016 it seems like its november 6th)
Also dont create the appointment on november 5th. create it on november 20th or something and move it.. if you create it on november 5th the glitch doesnt occur.
https://www.screencast.com/t/crRfhIsfL
See this video I am using : http://js.syncfusion.com/demos/web/dashboard/hospitalmanagement/default.html
I can also reproduce in my own code.
Only happens on November 5th 2017 (also november 6th 2018)
My timezone is UTC -4