JP and NA/EU servers are both being upgraded and more server worlds are being added to "Both" server hubs. The very fact that you think they shouldnt worry about the japanese either makes you A> A racist, or B> Completely ignorant.

If you havnt noticed the flux of players in both JP and NA/EU servers the entire game itself is full not just the NA/EU servers. To pick the time they did is the most viable option as that is the time in NA/EU that they have the highest peak players, taking it down then ensures that everyone is waiting and there is no obituary load on servers right before shutdown. Its just a simple matter of getting things done right when all the employees are still actually awake and not tired from a long days work.

Stop complaining about when they do it and just move on. Servers are going to be down no ifs ands or buts, and when they do come back up expect a short few hours of 1017 as everyone will be trying to get on, So just think of it as a good time, since the maintenance will be done in the early AM's for NA/EU, when you (if you even work) get off of work, the servers should be in stable gaming ability.

~nuff said