Oops, it doesn't look like 'get a sense of humor day' is a national day..

Other days

boba

Boba Day
carpenters

Carpenters Day
hiv awareness

Hiv Awareness Day
cuddle up

Cuddle Up Day
reading

Reading Day
tulip

Tulip Day
blanket fort

Blanket Fort Day
lash

Lash Day
china

China Day
martini

Martini Day