Oops, it doesn't look like 'dress as a farmer day' is a national day..

Other days

law

Law Day
my little pony

My Little Pony Day
lost sock memorial

Lost Sock Memorial Day
bow tie

Bow Tie Day
bubble bath

Bubble Bath Day
book

Book Day
gum

Gum Day
youth

Youth Day
one

One Day
ponytail

Ponytail Day