On May 3rd, the whole world annually celebrates the Sun Day.

Sun Day was designated in 1978 by United States President Jimmy Carter, specifically devoted to advocacy for solar power, following a joint resolution by Congress, H.J.Res. 715 becoming Pub. L.Tooltip Public Law (United States) 95–253. It was modeled on the highly successful Earth Day of April 22, 1970. It was the idea of Denis Hayes, who also coordinated Earth Day in 1970. The date became an international event in 1994, initiated by the European Section of the International Solar Energy Society (ISES).

Links:
May 3rd – International Sun Day