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

Other days

slime

Slime Day
nail polish

Nail Polish Day
bounce

Bounce Day
coffee

Coffee Day
ride the wind

Ride The Wind Day
lash

Lash Day
first love

First Love Day
kale

Kale Day
aloxolt

Aloxolt Day
prosecco

Prosecco Day