Realm restarting message

I've been screwed so many times by server maintenance, and I didn't think GGG warned when they did where taking the servers down, but people are saying that they warn you. Where do they warn you at. I can't get a straight answer from google searching, AI gives me wildly different answers, and I can't find a photo of it.
So where do they list the realm going down in X minutes warning?

Normally a message in yellow text above the chat pannel.

Sometimes it fades away but opening the chat pannel should make it pop back up, if its there.