Miitomo's next big update coming tomorrow

We've already detailed the new update for Miitomo, but now we know that it's coming tomorrow. Miitomo will be down for six hours to prepare for the update.

“Maintenance work will take place during the following period:
9/2/2017 4:00 UTC - 9/2/2017 10:00 UTC
(Please note that these times are approximate, and maintenance may conclude before or after the planned completion time.)
Purpose:
This maintenance is being conducted to prepare for the upcoming big update.
After maintenance is completed, you will be able to update your version of Miitomo. We hope you’re looking forward to this new version!
Please note that during the maintenance period it will not be possible to use Miitomo at all.
We apologise for the inconvenience, and ask for your understanding. Thank you!”