We will be deploying a software update on Thursday that will require downtime. The window for the downtime starts at 4PM and ends at 7PM your time. During that window, the site could be down for up to 1 hour, but should be operating normally for most of the window.
You may be interested in what's happening during this update. Ted wrote a blog post about it: the primary change is that the front page will have a "social feed" that will allow you to scroll through the content more easily.
I'll check in with you at some point after the update...but I might not be around directly afterwards, as I'm scheduled to take the afternoon off to visit my mom.