https://valkyrie-wow.org/realms/
"Important Information
We have scheduled maintenance every Wednesday at 03:00 AM GMT. This is the new official time and will not change. Maintenance usually lasts for 10 to 30 minutes, and during that time the honor system and rankings will update. If the server is down for any longer than the scheduled time — visit our forums and look for recent announcements. Staff test Realm is a developer sandbox and thus isn't suited for playtesting. Use Player Test Realm if you want to test the upcoming changes."
That would be Tuesday 10:00pm EST.
This will be a big issue for NA guilds across all time zones and clearly favors EU/RUS/OCE. I am not sure when this page was last updated though.
Will this be changed to appease to an international player-base? We ran into the same issues on early Nost, which a few guilds asked for this to be pushed back as certain guilds raided up until 01:00am EST (06:00am GMT).
I know details probably can't be given at this time, but I will not be able to attend the AMA and this is big.
I will be raiding EU times, just looking out for my old homies and future NA players.