Oops, it doesn't look like 'Fandoms day' is a national day..

Other days

ride the wind

Ride The Wind Day
offer

Offer Day
nae nae

Nae Nae Day
ask out your crush

Ask Out Your Crush Day
ruby

Ruby Day
one

One Day
slime

Slime Day
cat girl

Cat Girl Day
raise awerness of zeus

Raise Awerness Of Zeus Day
law

Law Day