Oops, it doesn't look like 'flag high on independence day' is a national day..

Other days

tulip

Tulip Day
buddy

Buddy Day
hoodie

Hoodie Day
slime

Slime Day
gum

Gum Day
brow

Brow Day
youth

Youth Day
aloxolt

Aloxolt Day
lost sock memorial

Lost Sock Memorial Day
bounce

Bounce Day