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

Other days

tulip

Tulip Day
ride the wind

Ride The Wind Day
artists

Artists Day
slime

Slime Day
youth

Youth Day
bounce

Bounce Day
bow tie

Bow Tie Day
kiss a ginger

Kiss A Ginger Day
law

Law Day
pumpkin

Pumpkin Day