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

Other days

african immigrant and refugee hiv and hep awareness

African Immigrant And Refugee Hiv And Hep Awareness Day
lost sock memorial

Lost Sock Memorial Day
unicorn

Unicorn Day
blanket fort

Blanket Fort Day
chocolate milkshake

Chocolate Milkshake Day
buddy

Buddy Day
stress awareness

Stress Awareness Day
ask out your crush

Ask Out Your Crush Day
me

Me Day
law

Law Day