Thanks for that link! I see the last post is by Nano and says: 
  
"The reset time will be 10am GMT +1 for Raid Resets and server updates, if needed. This is the final decision." 
  
This would be 4am EST, which is exactly what I suggested and what I believe Nost was, which is great; but Nano's post was made on the 15th and I had a ZG reset mid-raid on the 22nd. So I guess my suggestion is to sync raid resets with weekly maintenance so everything occurs at 10am GMT+1 (if this is not how it currently is and the ZG reset was a bug).