Oops, it doesn't look like 'magnitude will coincidentally happen the same day' is a national day..

Other days

brow

Brow Day
gallery

Gallery Day
african immigrant and refugee hiv and hep awareness

African Immigrant And Refugee Hiv And Hep Awareness Day
healing

Healing Day
self appreciation

Self Appreciation Day
blanket fort

Blanket Fort Day
ruby

Ruby Day
ask out your crush

Ask Out Your Crush Day
appreciate yaself a lil extra

Appreciate Yaself A Lil Extra Day
singles

Singles Day