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

Other days

kale

Kale Day
pick me

Pick Me Day
buddy

Buddy Day
bow tie

Bow Tie Day
ormille

Ormille Day
artists

Artists Day
lumpy rug

Lumpy Rug Day
china

China Day
offer

Offer Day
cat girl

Cat Girl Day