On the 15th day of the 12th lunar month, people rush to buy banh chung to worship, revealing the lucky time to pray.

According to cultural researchers, the word "chap" is a variation of the word "lap" in Chinese. Thieu Chuu dictionary says, "lap" is the ceremony to worship gods in the last month of the lunar year. According to the Zhou Dynasty, the year-end ceremony is called dai lap.

Vietnamese culture is heavily influenced by China, December is also a month of many ceremonies and worship. Vietnamese people also attach importance to visiting graves, incense tables, and ancestral altars at the end of the year, so that when the year ends and the New Year comes, they can burn incense and invite their ancestors to come home to celebrate Tet.

Another explanation for December: "lap" in Chinese also means meat. Tran Van Chanh's dictionary writes that: lap is salted food (in December), dried or salted for storage. The end of the year is when people stock up on food to fight the cold winter and also to prepare for Tet.

The full moon of December every year is the 15th day of the 12th lunar month. This is the last full moon day of the year before the Lunar New Year. After the full moon worship, everyone will be busy preparing for the Lunar New Year.

According to the lunar calendar, the full moon of December this year will be January 14, 2025.

For Vietnamese people, December is an important month of the year, when everyone looks forward to Tet and family reunion. Everyone is busy and tries their best to complete their plans for the year so that when the new year comes, they can look back on the old year and see many achievements.

Offering on the Full Moon of December means praying for luck, peace, remembering ancestors, and thanking the gods for their protection and blessing. On the Full Moon of December, people often go to the temple to pray and give thanks to the gods.

Offerings on the Full Moon of December are also considered a year-end offering. Therefore, the Full Moon offering is often prepared carefully and meticulously. The offering tray for the Full Moon offering usually includes sticky rice with gac fruit, boiled chicken, ham, sausage, sweet soup (usually sweet rice balls), fruits, white wine, and votive paper money.

According to feng shui experts, it is best to make offerings during the day, avoiding making offerings in the evening or too late. There are 3 suitable times to make offerings this year.

Hour of At Mao (5am-7am): This hour is quiet, good for opening ceremonies and worship ceremonies.

Dinh Ty hour (9am-11am): This is considered the auspicious hour of the day. If you worship at this hour, the homeowner will have a smooth year ahead.

Canh Than hour (3-5pm): This is also a suitable time of day to perform the full moon worship ceremony.

However, depending on the work and actual situation of each family, people can arrange suitable time for full moon worship.

In modern life, the full moon day of the twelfth lunar month still retains its value. Families often hold ceremonies on the 14th or 15th day of the lunar calendar. This is also an opportunity for people to express their gratitude to their ancestors and preserve traditional cultural values.

People in 2025 still maintain the tradition of offering banh chung on this day. Ms. Vu Thi Hai (Nam Tu Liem district, Hanoi), owner of a banh chung shop, said that in recent days she has continuously received orders to buy banh chung to offer on the 15th day of the 12th lunar month. The number of customers ordering has increased so quickly that she has had to hire more people to help with the cake making.

"To make a batch of banh chung, it takes at least a day and a night, with the steps of soaking beans, selecting leaves, wrapping the cake, and boiling the cake. Each pot can only boil about 20-30 cakes, while every day I receive hundreds of cakes ordered by customers, so I have to hire nearly 10 more people to help day and night and increase the number of pots to boil the cakes," said Ms. Hai.

Continuously checking the pots of banh chung being boiled to deliver to customers before the full moon offering in December, Ms. Hai said: "From yesterday to early this morning, I made about 150 banh chung, and by late afternoon I had delivered about 1 pot of 50 more. Due to the sudden increase in orders, the preparation and delivery of the cakes was very difficult, the shipper had to run back and forth many times."

According to Ms. Hai, on the first day of the lunar month or the full moon day, customers often choose to buy banh chung to worship their ancestors. But the first and full moon days of the twelfth lunar month are the most crowded. Because this time is near Tet, people often want to buy banh chung early to enjoy the taste of Tet. Because of the high demand, along with the sharp increase in input prices of ingredients, the price of banh chung on the full moon day of the twelfth lunar month is expensive, many types are even double the price of normal days.

Ms. Hai’s facility currently sells two types of banh chung: regular banh chung with traditional fillings for 100,000 VND/piece, and green rice banh chung for 140,000 VND/piece. This price at production facilities has doubled compared to normal days, and retail prices at stores may be even higher.

Meanwhile, Ms. Nguyen Thuy Hang (Thanh Tri district, Hanoi) said that for the past 2 or 3 days, she has stopped accepting orders for banh chung for the 15th day of the 12th lunar month, only accepting orders for delivery in the next 2-3 days.

"My family wraps the banh chung themselves, and on average we sell about 30-50 banh chung each day. However, before the full moon of the twelfth lunar month, the number of orders for banh chung had reached more than 100. Because we could not make them in time, I had to announce early that we would no longer accept orders for delivery on the full moon day, and would only continue to accept orders for delivery on the following days until Tet," said Ms. Hang.