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

Other days

nae nae

Nae Nae Day
fiancee

Fiancee Day
stud

Stud Day
my little pony

My Little Pony Day
hannah

Hannah Day
bounce

Bounce Day
blanket fort

Blanket Fort Day
bonang

Bonang Day
donate your hair

Donate Your Hair Day
reading

Reading Day