We're planning some changes to how we deliver the site. We'll undertake this during the day today, Whilst it shouldn't even be noticed by you guys we'd like to make everyone aware it could potentially make the site unavailable! We'll begin work roughly in the next hour and work until completion. This change, whilst not necessary is a start to some bigger changes we want to undertake and will allow those to be completed without downtime.
If you get any errors during those times, don't panic it's temporary!