Have they said anything about when the game will be put up on the eshop?
In theory, it would be midnight NYC time, as that's when they're launching it in North America.
I've googled, but I can't find a specific Japanese release time, beyond that it's on the same day. If they held it til midnight NYC, that would have the game launch at 1pm for Japan, which is mildly late in the day, but not impossibly late.
Or are they just having the worldwide launch be day related, rather than time related?