Oops, it doesn't look like 'assembly to commence sitting for the day' is a national day..

Other days

girl friend

Girl Friend Day

boba

Boba Day

polyamory

Polyamory Day

ponytail

Ponytail Day

unicorn

Unicorn Day

eat what you want

Eat What You Want Day

pick me

Pick Me Day

Me Day

youth

Youth Day

tell ur crush you like them

Tell Ur Crush You Like Them Day