Oops, it doesn't look like 'sworn sibling day' is a national day..

Other days

prescription drug take back

Prescription Drug Take Back Day
african immigrant and refugee hiv and hep awareness

African Immigrant And Refugee Hiv And Hep Awareness Day
my little pony

My Little Pony Day
self appreciation

Self Appreciation Day
self care

Self Care Day
stress awareness

Stress Awareness Day
nail polish

Nail Polish Day
cursing

Cursing Day
reading

Reading Day
prosecco

Prosecco Day