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

Other days

artists

Artists Day
promposal

Promposal Day
frozen yogurt

Frozen Yogurt Day
youth

Youth Day
cuddle up

Cuddle Up Day
self care

Self Care Day
polyamory

Polyamory Day
bow tie

Bow Tie Day
gallery

Gallery Day
martini

Martini Day