An age-old harvest tradition begins today with East Asian communities around the world celebrating the first full moon of fall.

Based on the lunar calendar, the Mid-Autumn Festival corresponds with the bright orange glow of the Harvest Moon. Many people take off work to gather with their families, light lanterns, enjoy mooncakes and gaze at the luminescent night sky. To mark the seasonal holiday, Google created an autumnal Doodle featuring tea, mooncakes and the reflection of a full, bountiful moon.

As celebrations kickoff, here’s what to know:

What is the Mid-Autumn Festival?

Known by various names throughout Asia, including Moon Festival and Harvest Moon Festival, the mid-autumn ritual was popularized more than a thousand years ago during China’s Tang dynasty (618–907 CE).

While it has no fixed date on the Gregorian calendar, the holiday is traditionally celebrated on the 15th day of the 8th month in the East Asian lunar calendar. It corresponds with the first full moon after the Autumnal Equinox. This year, celebrations start on Sept. 24.

The holiday is also associated with the Chinese moon goddess Chang’e. As legend has it, Chang’e overindulged on the “elixir of life” and ascended to the moon. She is fated to remain there, accompanied by her jade rabbit and a lumberjack.

This week, festival-goers will offer fruit, wine and mooncakes to the wayward goddess in hopes of ensuring an abundant harvest.

Read more: Five Things to Know About the Mid-Autumn Festival

Where is it celebrated?

Major celebrations take place in China, Hong Kong, Taiwan, Japan, Singapore, Korea, Malaysia, Vietnam and the Philippines. Many in the East Asian diaspora also observe the holiday, with families in the U.S., Europe and elsewhere gathering to mark the autumn thanksgiving festival.

In Vietnam, where the holiday is known as Trung Thu, children play games, don masks and march in nighttime lantern parades.

In Korea, the holiday is known as Chuseok, and has a strong association with heritage. Many people return to their hometowns to visit the graves of their ancestors, which they clean before making offerings.

dance team performs the Fire Dragon Dance to celebrate the Mid-Autumn Festival in Hong Kong on Sept. 23, 2018.

Anthony Kwan—Hong Kong Tourism Board/Getty Images A

How is it celebrated?

One of the most common ways people celebrate the Mid-Autumn Festival is by enjoying mooncakes — a dense sweet pastry that is baked or steamed and then cut into wedges and accompanied by tea. Traditionally, mooncakes are filled with with lotus paste and salted egg yolk. Other varieties contain red bean or date paste, as well as nuts, fruits and seeds.

Modern mooncakes also cater to contemporary tastes: the treats are now available in flavors like taro, green tea, chocolate and ice cream. This year, Guinness even released its own flavor.

Many communities also celebrate by making and lighting paper lanterns. Traditionally, lanterns were handmade and painted, and illuminated with candles. Today, most versions use electric bulbs. More ornate lanterns feature rattan or wooden skeletons that supports shapes like animals, stars, planets and more.

Some neighborhoods also celebrate by hosting lion and dragon dances, where dance troupes parade through the streets to bestow luck on local residents.

However you celebrate the harvest holiday, have a Happy Mid-Autumn Festival!