More than a billion people across the world, from China to the Philippines to diaspora communities in the United States, began celebrating the Lunar New Year on Tuesday with fireworks, family time and feasts.

On Wednesday, the first new moon of the Year of the Snake will mark the imminent arrival of spring.

Known as Seollal in South Korea and Tet in Vietnam, the beginning of the lunisolar year is the most important holiday in many Asian countries. In China, it prompts the world’s largest annual migration. Hundreds of millions of people brave jammed roads, train stations and airports, many making the exodus from major cities to their hometowns.

Lunar New Year traditions vary across and within countries, but similar threads run throughout: family time, rituals for prosperity and to honor ancestors, and marathon feasts. Many flock to temples to place offerings of traditional food, and light incense at altars for ancestors and elders.

In China, children receive red envelopes as blessings from their relatives. In Southeast Asia, dragon dances, believed to bring good luck, prosperity and rain, are held in the streets — and sometimes underwater.

Here’s how people said goodbye to the Year of the Dragon and welcomed the Year of the Snake: