(CNN) — It's time to hang a lantern, rip open a mooncake and peel a pomelo -- Mid-Autumn Festival is here.

Falling on the 15th day of the eighth lunar month, Mid-Autumn Festival, or Moon Festival, is when families gather to sample autumn harvests , light lanterns and admire what's believed to be the fullest moon of the year.

In 2019, the event --- celebrated primarily in East and Southeast Asia -- falls on September 13. Here's a bit of background and a few tips on how to join this massive full moon party.

What are the origins of Mid-Autumn Festival?

The Mid-Autumn Festival is widely celebrated around Asia. Lam Yik Fei/Getty Images AsiaPac/Getty Images

Mid-Autumn Festival became an official celebration in China during the Tang Dynasty (618-907 CE) but there isn't one single answer to the question of when and how the Mid-Autumn Festival began.

Many believe the fete was first mentioned in the "Book of Rites," a Confucius classic on bureaucracy and rituals written more than 2,400 years ago.

It was described as a day for emperors to celebrate the year's harvest by giving offerings to the moon and hosting a great feast.

Today, the Mid-Autumn Festival is an incredibly important family gathering -- it's when "people and the moon reunite to form a full circle," as an old saying goes.

Chang'e: The moon festival goddess

Like many cultural celebrations, the Mid-Autumn Festival is shrouded in myth. One of the most beloved -- and tragic -- pieces of folklore tells the story of how Chang'e became the moon goddess.

According to the legend, after mythological Chinese archer Hou Yi courageously shot down nine surplus suns -- leaving only one, in effect protecting the world from being scorched completely -- he was given an elixir from heaven.

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Hou Yi's wife Chang'e drank the elixir while protecting it from a greedy apprentice, but became so light that she floated to the moon.

Missing his wife, Hou Yi prepared a feast every year on the day when the moon is at its fullest, hoping to get a glimpse of his wife's shadow.

Yutu (Jade Rabbit) -- China's moon rover -- was named after the legendary rabbit that was sent to accompany Chang'e to the moon.

How to celebrate?

The Tai Hang fire dragon dance is performed in Hong Kong. Courtesy Hong Kong Tourism Board

When it comes to the festival, customs vary throughout Asia.

The Mid-Autumn Festival is considered "children's day" in Vietnam and celebrations include paper lantern fairs and lion dance parades. Meanwhile, in southern China, most people will light a lantern and eat autumn fruits such as pomelo and starfruit.

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Some villages in Hong Kong still preserve the tradition of fire dragon dancing through a narrow alley.

In South Korea, the mid-Autumn Festival is a three-day holiday, a time to sweep ancestors' tombs and wear traditional attire.

Japanese, meanwhile will eat grilled sticky rice balls called tsukimi dango ("moon viewing") while admiring the astronomical body.

All about mooncakes

Mooncakes come in all sorts of shapes and flavors. CNN

One of the biggest stars of the Mid-Autumn Festival is the mooncake -- it's as important to festivities as turkey is to Thanksgiving and latkes are to Hanukah.

The calorie-packed pastry is sliced up and shared like a cake between families and friends.

The most common kind of mooncake is made of lotus seed paste, salted egg yolk and lard -- which explains why a palm-sized cake can contain about 1,000 calories.

Nuts, red beans and custards are some other popular ingredients.

In recent years, big brands have taken to creating specially designed mooncakes. The Palace Museum in Beijing, for example, offers some particularly stunning ones.