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

Other days

comfy

Comfy Day
reading

Reading Day
cursing

Cursing Day
boy friend

Boy Friend Day
aloxolt

Aloxolt Day
girl friend

Girl Friend Day
boba

Boba Day
nae nae

Nae Nae Day
slime

Slime Day
camera

Camera Day