National Air Quality Awareness Week in USA

Greenery Day in Japan on May 4 (みどりの日 - Until 1988, April 29 was celebrated as the birthday of Emperor Showa. It was decided to keep this day a holiday even after his passing away in January 1989 and to name it Greenery Day because of the late Emperor's love of nature. In 2007, April 29 became Showa Day, and Greenery Day was moved to May 4);

World Hand Hygiene Day on May 5;

World Pulmonary Hypertension Day on May 5;

Mental Health Week in Canada on May 5 (Held in the first full week of May);

National Nursing Week in Canada on May 5 (Held from Monday to Sunday of the same week in which the date May 12 is located);

Sun Awareness Week in Canada on May 5 (Held from the first Monday in May);

International Handwashing Day on May 5 (since 2009, when the WHO Patient Safety Program launched a new initiative called Save Lives: Wash Hands);

Orthotist and Prosthetist Day in El Salvador on May 5 (Día del ortesista y protesista);

Celiac Awareness Day in Argentina on May 5;