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

Other days

believe

Believe Day

bonang

Bonang Day

Me Day

slime

Slime Day

healing

Healing Day

first love

First Love Day

pick me

Pick Me Day

tell ur crush you like them

Tell Ur Crush You Like Them Day

stress awareness

Stress Awareness Day

prosecco

Prosecco Day