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

Other days

fiancee

Fiancee Day
cat girl

Cat Girl Day
bow tie

Bow Tie Day
boyfriend

Boyfriend Day
ruby

Ruby Day
pick me

Pick Me Day
latina equal pay

Latina Equal Pay Day
boba

Boba Day
donate your hair

Donate Your Hair Day
aloxolt

Aloxolt Day