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

Other days

special education

Special Education Day
boba

Boba Day
hannah

Hannah Day
nae nae

Nae Nae Day
lost sock memorial

Lost Sock Memorial Day
carpenters

Carpenters Day
boy friend

Boy Friend Day
one

One Day
comfy

Comfy Day
coffee

Coffee Day