When people from a small village on North Efate have a celebration day, they call it a festival. Others call it Christmas, Hanukkah, Easter, Ramadan, etc. And they do what everyone else does: get together, get pissed, sing, dance, communicate with outer worlds.
Take the Two Moon Festival. It too has its celestial origins. Some 10 years ago the Survivor show came to film on the island. They were shooting a scene, and the moon was not where it would look best on the show. The way to solve the problem was to cut out a card-board moon and hoist it on a bamboo scaffolding. All fine, till the locals took notice that there were two moons up in the sky! Out came the shamans, the drums, the kava, the all-night dancers. There you go – a new religious celebration. Every year now, on the same date.