Polish National Flag Day celebrations held in Warsaw

Polish President Andrzej Duda (R, center) and his wife Agata Kornhauser-Duda (L, center) attends Polish National Flag Day celebrations in Warsaw, Poland, on May 2, 2018. Polish National Flag Day, which falls between Labor Day on May 1 and Constitution Day on May 3, has been celebrated in Poland since 2004. (Xinhua/Jaap Arriens)