According to Nintendo’s network status page,
from 5:00pm Pacific on Monday March 24th to 1:00am on the 25th, the
Nintendo 3DS network will be undergoing “extended maintenance” in
addition to that week’s usual Monday noon to 4:00pm updates. Apparently
there was some maintenance for the
Pokémon X and Y online services yesterday evening, as well. If you had trouble playing Pokémon online yesterday, there’s your reason.
this just means that some online features will be down during
maintenance, but it does pique the curiosity as to what Nintendo is
working on that warrants extra downtime. Probably just fine-tuning, if
we want to be realistic.