And it doesn't stop there. Back in 2014, around summer solstice, the bug off was also participating as well. Though the bug off is not a real event, talk to Isabelle. As its the only year she'll ever say something unique.
This is actually interesting though! :3 I had no idea that if holidays landed on the same day you could celebrate both, that's very neat~ I can't wait until this date hits (but I'm not gonna lie I sort of hope a new AC is out by then lol?).