Here's what the host said about it:
For the coming week, Monday through Friday, we are scheduling maintenance windows between 10pm and 11pm Arizona time (5:00am to 6:00am UTC). At some point during each window, we may (not “we will”) shut down our master database for five minutes to make sure everything works as expected, and that it comes back up properly afterward.
Of course, things often don't go as planned. Hopefully this will be a smooth bit of work, though.