Maintenance for the week of August 31:
• NA megaservers for maintenance – August 31, 4:00AM EDT (8:00 UTC) - 12:00PM EDT (16:00 UTC)
• EU megaservers for maintenance – August 31, 8:00 UTC (4:00AM EDT) - 16:00 UTC (12:00PM EDT)
• ESO Store and Account System for maintenance – August 31, 4:00AM EDT (8:00 UTC) - 12:00PM EDT (16:00 UTC)
From this morning's PTS Patch Notes
The issue many Mac users have been experiencing is specifically called out for a fix:

This is the first time I've seen the "Mac game client" specifically named in the patch notes. I plan to test this out on PTS, and encourage other Mac users will do the same. I'm cautiously optimistic.