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

Other days

lash

Lash Day
buddy

Buddy Day
coffee

Coffee Day
boba

Boba Day
bow tie

Bow Tie Day
hoodie

Hoodie Day
ruby

Ruby Day
aloxolt

Aloxolt Day
slime

Slime Day
pampering

Pampering Day