Fifty nine year widest ranging social gathering. I think this is this thing that came out of the WWII. Remember your neighbors.
"The anniversary of the entry into force of the United Nations Charter on 24 October 1945 has been celebrated as United Nations Day since 1948. It has traditionally been marked throughout the world by meetings, discussions and exhibits on the achievements and goals of the Organization. In 1971, the General Assembly recommended that Member States observe it as a public holiday.
(resolution 2782 (XXV). (Reference Paper 45)."