On Monday, 10/3, we are performing a mandatory maintenance on our Northamerican and European datacenter beginning at 2am EDT / 7:00 BST which causes all megaservers as well as the PTS, the store and the account page to be offline.
We anticipate downtime to be approximately 8 hours. We'll let you know when maintenance is nearing completion.
Thanks for your understanding and patience.
Community Manager - The Elder Scrolls Online