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

Other days

pampering

Pampering Day

african immigrant and refugee hiv and hep awareness

African Immigrant And Refugee Hiv And Hep Awareness Day

healing

Healing Day

Emoji Day

stress awareness

Stress Awareness Day

girl friend

Girl Friend Day

hannah

Hannah Day

ask out your crush

Ask Out Your Crush Day

eat what you want

Eat What You Want Day

polyamory

Polyamory Day