Hi, all: we're doing a security update tomorrow! Yippee!
The maintenance window will be from 4:00 PM on the 28th to 4:00 AM on the 29th (your time). During the maintenance window, there will be occasional outages of up to 30 seconds. If you bump up against an error screen (or super-slowness), just try again in a minute.
*waits for Saint*