The June 1 holiday, observed in Poland and many other former Eastern Bloc countries, dates back to the early 1950s and coincides with International Children’s Day in those states, while the United Nations marks World Children’s Day on November 20, the anniversary of the 1959 Declaration of the Rights of the Child and the 1989 Convention on the Rights of the Child. Celebrations in Warsaw began over the preceding weekend, when the gardens of the Prime Minister’s Chancellery hosted an annual family picnic under the theme “Land of Imagination,” to which Prime Minister Donald Tusk invited children and their guardians. From May 30 to June 1, passengers on Warsaw buses, trams and metro trains heard stop names read out by child voice‑over artists on selected routes, a special series of announcements prepared jointly for Mother’s Day and Children’s Day. In southern Poland, regional authorities in the Małopolska and neighboring regions introduced a symbolic 1 złoty ticket for young passengers on selected trains and buses to mark the holiday.