Oops, it doesn't look like 'cheer up renjun day' is a national day..

Other days

boba

Boba Day
hoodie

Hoodie Day
book

Book Day
fiancee

Fiancee Day
cat girl

Cat Girl Day
lash

Lash Day
lumpy rug

Lumpy Rug Day
donate your hair

Donate Your Hair Day
buddy

Buddy Day
youth

Youth Day