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

Other days

first love

First Love Day
gum

Gum Day
my little pony

My Little Pony Day
tulip

Tulip Day
believe

Believe Day
latina equal pay

Latina Equal Pay Day
carpenters

Carpenters Day
self care

Self Care Day
ormille

Ormille Day
artists

Artists Day