Yesterday at 4PM Eastern, USPTO posted a plan:
While systems have been coming back online throughout the day, we intend to take them out of service beginning at 10:00 p.m. ET tonight [yesterday evening August 21]. Our onsite experts will be working throughout the night to further optimize system performance. We anticipate that the systems will be back online tomorrow morning [today August 22].
I told USPTO that it would have been more user-friendly for USPTO to schedule this takedown for 12:01 AM ET. But the takedown proceeded yesterday evening as described in the posted plan. The systems are still down now, at 6:42 AM ET.