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

Other days

donate your hair

Donate Your Hair Day
martini

Martini Day
youth

Youth Day
special education

Special Education Day
self appreciation

Self Appreciation Day
brow

Brow Day
buddy

Buddy Day
self care

Self Care Day
chocolate milkshake

Chocolate Milkshake Day
eat what you want

Eat What You Want Day