Maintenance for the week of October 5:
• [COMPLETE] ESO Store and Account System for maintenance – October 8, 8:00AM EDT (12:00 UTC) – 12:00PM EDT (16:00 UTC)
I paid right away on the 4th, early afternoon, right when I got home from work because I knew something like this would happen. The extra day wasn't worth the potential for problems.
That said, though, I too was in queue to get on the website; luckily it only lasted for about 10 minutes, and there were 100 people ahead of me.