I noticed it this morning around 4AM. I actually posted this thread between downtimes, it was down just before, came up a bit, and then went down again. Yesterday morning it was down for a while, from just before 2AM to about 5AM. Other days I can't give specific times on, but it feels like it's been down at least six of the last seven nights.
I work the graveyard shift, so I'm on ALL NIGHT because I have nothing to do at work, so I tend to notice these things. It's one of those issues where I hit the bookmark, the page loads for a moment, and then says it's down. If I reload, it thinks for less than a second before saying it's down again.