Hetalia Day this year lands on October 21st!
Hetalia, though a smaller fandom now, is still celebrated alongside UN Day with its own Hetalia meetup. These meetups happen everywhere around the world, and you can check for the closest meetup near you here: http://hetalia-day.com/directory/
As for me, I'm hosting Hetalia day in San Francisco! If you live in the SF Bay Area (or will be in the area during the 21st), come and join! Cosplays are of course allowed (though the main coordinator of the entire event has stated that Hetalia cosplays are preferred, as it is a Hetalia meetup, but other fandoms are welcome at mine). There will be games and activities, and I will also have prizes!
My meetup is on the 21st of October, at 12PM (noon) at the Japantown Peace Plaza. THIS EVENT IS FREE! Yay!
Check out the Facebook event page: https://www.facebook.com/events/1166359443464028/
Responding to the event through this page would be great so I can get an idea of how many people might go. If you don't have a FB, PM me and I'll add you to the tally.