Oops, it doesn't look like 'vanilla milkshake ice cream soda hollerincontest day' is a national day..

Other days

bow tie

Bow Tie Day
china

China Day
self appreciation

Self Appreciation Day
ruby

Ruby Day
youth

Youth Day
me

Me Day
bounce

Bounce Day
singles

Singles Day
pick me

Pick Me Day
blanket fort

Blanket Fort Day