Clearly they should invent a day and time that exists outside the normal space-time continuum, because that's the only way to avoid somebody crying over downtime on any given day/time, ever.
They need to launch a probe containing the server, and somehow anchor it within the event horizon of a black hole. The gravitational time dilation may just do the trick if used cleverly!
I wish to point out to the ESO support team that in a large part of the world the week-end runs from Friday to Saturday.
If ESO wanted to maintain the server before the week-end they should have done it on Thursday
Now the week-end in a big part of the world has started and the server is down.
Not very well thought out I think.
Oliewabie