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

Other days

artists

Artists Day
gum

Gum Day
ask out your crush

Ask Out Your Crush Day
boy friend

Boy Friend Day
one

One Day
brow

Brow Day
unicorn

Unicorn Day
cuddle up

Cuddle Up Day
pumpkin

Pumpkin Day
blanket fort

Blanket Fort Day