A island-wide Balinese festival occurring once every hundred years. The name translates to "Festival of the 11 Powers". It is a 11-week-long ceremony, and the fate of the universe hangs in the balance.
The whole country celebrates, bringing immense amounts of very artistically designed food for the Gods (Siva) and Demons (Rudra), who will be brought together at the height of the ceremony. If it works, the gods will be re-born as demons and vice versa.
In 1963 President Sukarno tried to bring the eka desa rudras about early. This is allowed in cases of great turmoil, particularly extreme natural disasters, and the Indonesian revolution was deemed to be sufficiently tragic; also, it would help settle the masses down. But the premature festivities were ruined by the first recorded explosion of Bali's volcano, Gunung Agung, killing over 1,500 people.
The Eka Dasa Rudra was redone at the correct time, on March 28, 1979 (the Balinese calendar is different than ours; this was a millennial year for them). The results of the festival would not be known for a long time; if it was successful, the world is okay for the next hundred years; if it failed, the world will end. It's been over 20 years now, and I still can't find out what the results were.