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

Other days

cat girl

Cat Girl Day
ask out your crush

Ask Out Your Crush Day
comfy

Comfy Day
ruby

Ruby Day
boy friend

Boy Friend Day
youth

Youth Day
china

China Day
my little pony

My Little Pony Day
brow

Brow Day
hiv awareness

Hiv Awareness Day