Shui Duan Festival in Sandu
The Duan Festival of the Shui people, centered in Sandu Shui Autonomous County, Guizhou, is widely cited as the world's longest festival at forty-nine days, structured so that up to seven branch communities each celebrate their own new year on staggered dates within that window. Horse racing, a tradition uncommon elsewhere in China, marks the festival alongside harvest celebration and ancestor offerings, recognized as national intangible cultural heritage since 2006.
At forty-nine days, the Duan Festival of the Shui people is widely described as the longest-running festival in the world, a duration that exists specifically to accommodate as many as seven different branch communities celebrating their own new year on staggered dates rather than everyone marking the same day at once.