Around 4:00 AM CDT, the SDMB shuts down. Try to access the site, and you get the standard vBulletin database error page. Around 5:00, the site is up and running again.
The server clock is about eight minutes slow, currently, so the downtime starts at 03:38 CT and lasts to about 04:22. In my experience, you’ll get a timeout for about the first half of the downtime, and the standard database error page that you mention for the second half.