More like a week, to be precise IF you're not reported while being banned as that seems to extend the duration of the ban.
Man, how did Nintendo mess this online report system so bad.
Btw, people, I've been out of banland for a month and on my best behavior. I'm pretty sure I've been reported already by some (definitely blocked by some) and so far I haven't been back in banland, so I personally couldn't testify how easy it is for an ex-con to get sent back to banland. Some people reported going back in as quickly as 24 hours, so who knows what's real.
But I gotta say, before my first ban, female players were rare. Now they're like 1/4th of my matches. Considering how sexist the gaming community can be towards women, what with their demands for them to return to a kitchen to put together a sandwhich, I kinda wonder. Have I been banned again, but I've been placed in a much larger server, one where there are a lot of female players who have been reported due to beating salty 13 year olds who couldn't handle losing to a woman (and the women I have played are pretty good. Like, "I get nervous if I'm paired with a female player" type good). I know it's weird because I do play against a diverse range of people and haven't been paired with the same person twice and that's like the opposite of the banned experience, but still. Considering that some people's ban experiences has been being paired with only Japanese players and others spend over 20 minutes with 0 matches vs my own experience where I would find someone quickly, except they'd be the same 7 people, it seems like all our experiences are different.
So I'm thinking I may be banned in a larger server? Perhaps Nintendo does review reports and categorize players based on crime? Foul language here. Tea-baggers there?
Just spitballing here.