Oops, it doesn't look like 'anthem at westminster abbey armistice day' is a national day..

Other days

lash

Lash Day

cuddle up

Cuddle Up Day

blanket fort

Blanket Fort Day

Emoji Day

first love

First Love Day

fiancee

Fiancee Day

boba

Boba Day

boy friend

Boy Friend Day

coffee

Coffee Day

embarrass your best friend

Embarrass Your Best Friend Day