Oops, it doesn't look like 'billions of spiders day' is a national day..

Other days

slime

Slime Day
tulip

Tulip Day
self care

Self Care Day
one

One Day
ruby

Ruby Day
nail polish

Nail Polish Day
buddy

Buddy Day
frozen yogurt

Frozen Yogurt Day
lash

Lash Day
lumpy rug

Lumpy Rug Day