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

Other days

bow tie

Bow Tie Day
reading

Reading Day
frozen yogurt

Frozen Yogurt Day
raise awerness of zeus

Raise Awerness Of Zeus Day
comfy

Comfy Day
gum

Gum Day
kale

Kale Day
ruby

Ruby Day
first love

First Love Day
coffee

Coffee Day