Oops, it doesn't look like 'move up a weight class day' is a national day..

Other days

china

China Day
slime

Slime Day
brow

Brow Day
mean girls

Mean Girls Day
promposal

Promposal Day
prosecco

Prosecco Day
self care

Self Care Day
pick me

Pick Me Day
cuddle up

Cuddle Up Day
singles

Singles Day