This worldwide initiative organized by the World Wildlife Fund is aimed against the greatest threat to the Earth - climate change. On Saturday 28 March, between 8.30 pm and 9.30 pm the event's participants all over the globe switched off lights in houses, businesses and public buildings. For the first time lights also went off in all office buildings of the PGE Capital Group.

Other institutions which joined the event included, among others, in Warsaw: the Palace of Culture and Science, the Chancellery of the Prime Minister, the City Bridges,   St. John's Cathedral and other churches; in Cracow: the St. Mary's Church,  Wawel Castle, the Kościuszko Mound, the National Museum, the Jagiellonian Library, the Słowacki Theatre; in Lublin:  Lublin Castle, the Osterwa Theatre, the Town Hall, the Metropolitan Cathedral, the Trinitarian Tower, the Dominican Basilica.