Talk:Nichijou Episode 0/@comment-24177998-20150423005729

Mio mentions the incident where Yukko remembers to do her homework but leaves it at home, which is in Episode 12; she also casually references her manga, and it seems she had a major issue with people knowing about it before Episode 20 or so.

So I'm thinking Episode 0 is most likely set well after between 4 and 5.