New events roll out on the Thursday 11am (5am Friday here in Aust).
The new Barons Tent cycles start on the Friday morning, unsure of the exact time but guessing 9am or 11am (so Sat here in Aust).
Then it depends on your tent cycle and when you log in - before the launch time you’ll get an extra day , after the launch and the new tent prizes will load and your Snowballs will be useless.
Hope that all makes sense and helps you plan.