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

Other days

nail polish

Nail Polish Day
coffee

Coffee Day
cuddle up

Cuddle Up Day
gum

Gum Day
offer

Offer Day
fiancee

Fiancee Day
ponytail

Ponytail Day
tulip

Tulip Day
my little pony

My Little Pony Day
donate your hair

Donate Your Hair Day