It is expected by this month we don't know exact date but it is first come first serve basis do watch out at samsung. Com for release stable beta. Hope this helps!
The Beta one ui 4.0 is being released this month, as of today, China, Korea and some parts of Europe have released the upcoming Beta, the Beta program will show up in the Samsung members application in the Banner area, once you have signed up for the Beta it takes a few minutes to be pushed to your phone, I also highly recommend that you Completely Backup your phone before you install the Beta software
