Round and round we go...These technical issues are frustrating for sure. The internet...hmmm.
I don't know exactly when they are switching servers. Lisa will announce it. She'll probably do it later on at night when traffic is down. It will have to be offline for a bit while they make the server change.
The last time they made the server change it wasn't down for very long. I can't tell you how long though there are a lot of mitigating factors that go into a smooth hand off.