Oops, it doesn't look like 'Infant Sibling day' is a national day..

Other days

bow tie

Bow Tie Day
boyfriend

Boyfriend Day
carpenters

Carpenters Day
african immigrant and refugee hiv and hep awareness

African Immigrant And Refugee Hiv And Hep Awareness Day
slime

Slime Day
camera

Camera Day
chocolate milkshake

Chocolate Milkshake Day
self care

Self Care Day
raise awerness of zeus

Raise Awerness Of Zeus Day
youth

Youth Day