Future Day was first publicly discussed at the Humanity+ Leadership: MINDS conference on September 15 2011 — in Second Life, an appropriately futuristic location!

The idea was floated by Humanity+ Vice Chair Ben Goertzel and enthusiastically received by Humanity+ Director Howard Bloom, Humanity+ Chair Natasha Vita-More, and a host of others in attendance. The rest is (future) history.

http://futureday.org