Oops, it doesn't look like 'Park During Hike On A Hot day' is a national day..

Other days

Embarrass Your Best Friend Day

African Immigrant And Refugee Hiv And Hep Awareness Day

One Day

Brow Day

Tell A Fairytale Day

Raise Awerness Of Zeus Day

Buddy Day

Emoji Day

Eat What You Want Day

Unicorn Day