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

Other days

buddy

Buddy Day
bow tie

Bow Tie Day
nail polish

Nail Polish Day
slime

Slime Day
martini

Martini Day
pick me

Pick Me Day
ruby

Ruby Day
kiss a ginger

Kiss A Ginger Day
hannah

Hannah Day
kale

Kale Day