Oops, it doesn't look like 'do a grouch a favor day' is a national day..

Other days

me

Me Day
my little pony

My Little Pony Day
pick me

Pick Me Day
self care

Self Care Day
first love

First Love Day
ormille

Ormille Day
cuddle up

Cuddle Up Day
mean girls

Mean Girls Day
artists

Artists Day
lumpy rug

Lumpy Rug Day