TL;DR: Rằm tháng Chạp (15th day of the 12th lunar month) is the last rằm of the year, when families often make offerings to Thổ công, the deities and ancestors to give thanks and pray for peace. The offerings are usually simple, not necessarily savoury, and include incense, flowers, betel and areca, and votive paper. This rằm is tied to the tất niên atmosphere, but it is not the official tất niên ceremony; tất niên is the year-end gathering of family, office or guild.
When is the Rằm of the Twelfth Lunar Month and Why Is It Valued?
Rằm tháng Chạp is the 15th day of the 12th lunar month, the last rằm of the year. According to the perpetual calendar, the rằm of the twelfth month in the Ất Tỵ year 2025 falls on Monday, 2 February 2026 in the solar calendar[1]. The rằm of the twelfth month in the Bính Ngọ year falls on 22 January 2027.
In the folk beliefs of the Vietnamese, the rằm of the twelfth month carries important spiritual meaning: it is an occasion for families to make offerings to thank Heaven and Buddha, the ancestors and the deities who protected them throughout the year, and at the same time to pray for luck, health and peace in the new year[1]. Many people hold that the rằm of the twelfth month is the "tất niên" of the lunar calendar, so the offerings are often prepared more carefully than at an ordinary rằm, though they need not be as large as a tất niên feast.
What Is Offered at the Rằm of the Twelfth Lunar Month?
Vietnamese families usually prepare a tray of food or a few offerings to present to Heaven and Buddha and to the ancestors[1]. The book Phong tục thờ cúng của người Việt (compiled by Song Mai and Quỳnh Trang, Văn hoá Thông tin Publishing House, 2006) states: "The first day of each month is the ngày Sóc, the full moon is the Vọng. On these days, families all prepare offerings to the ancestors, Thổ công, Thánh sư, Tiền chủ and Thần tài at the family altar."[2] That means on every sóc and vọng the family altar is set with offerings to these figures, and the offerings may be savoury (except when offering to Buddha) or limited to incense, flowers, betel and wine. As for the offerings, Bùi Xuân Mỹ in Tục thờ cúng của người Việt (Văn hoá Thông tin Publishing House, 2001) writes: "For the offerings on the ngày Sóc and ngày Vọng, the gifts are usually very simple: incense, lamps, betel, fruit, votive paper. A savoury offering is not required on this occasion."[3]
In practice, however, many families still prepare savoury offerings at the rằm of the twelfth month because it is the last rằm of the year, sometimes combined with the tất niên ceremony. Below is a comparison table of the usual offerings:
| Offering | Ordinary rằm | Rằm of the twelfth month |
|---|---|---|
| Incense, lamps, betel and areca, votive paper | Yes | Yes |
| Fresh flowers and fruit | Yes | Yes, often seasonal fruit |
| Savoury offering (sticky rice, chicken, meat) | Depends on the family, usually not required | More families prepare a savoury offering |
| Prayer text | Prayer to Thổ công and ancestors | Prayer to Thổ công and ancestors, sometimes with words of thanks for the year |
What Does the Prayer Text for the Rằm of the Twelfth Month Contain?
According to Văn khấn cổ truyền Việt Nam (Văn hoá Thông tin Publishing House), the prayer text for the rằm of the twelfth month consists of two main parts: the prayer to Thổ công and the deities, and the prayer to the ancestors[1]. The prayer to Thổ công usually opens with "Nam mô A Di Đà Phật" (3 times), then pays homage to the nine directions of Heaven, the ten directions of the Buddhas, Hoàng thiên Hậu thổ, the venerable deities, ngài Đông thần quân, Bản gia Thổ địa Long mạch, Ngũ phương Ngũ thổ, Phúc đức tôn thần, Tiền Hậu Địa chủ Tài thần, and the deities governing the area[1].
The ancestral prayer is usually shorter, offered to the family's ancestors, asking for protection so that the descendants may be peaceful, healthy and lucky in the new year. The head of the household recites the prayer text after the tray and offerings have been arranged[1].
How Does the Rằm of the Twelfth Month Differ from an Ordinary Rằm?
The basic difference lies in meaning and scale of the offerings. An ordinary rằm (in other months) is mainly a simple occasion, sometimes needing only incense, flowers, betel and water. The rằm of the twelfth month is the last rằm of the year, so the offerings are often prepared more carefully, and many families combine it with cleaning the altar, replacing the incense bowl, or preparing for Tết.
Second, the rằm of the twelfth month is tied to tất niên. According to Phong tục thờ cúng của người Việt, the tất niên feast is an occasion for business partners, officials and students to meet before parting to celebrate Tết[2]. The rằm of the twelfth month is not tất niên, but many families take the opportunity to hold the rằm ceremony and combine it with an early tất niên meal.
Third, psychologically, the rằm of the twelfth month often reminds people of the merits of ancestors and deities who protected them during the year, so the prayer may include words of thanks, not only requests as at an ordinary rằm.
Is the Rằm of the Twelfth Month the Same as Tất Niên?
No. The rằm of the twelfth month is the last full moon of the year, while tất niên is the year-end gathering of family, office or guild, usually held in the last days of the twelfth month (from the 25th to the 30th). According to Phong tục thờ cúng của người Việt, the tất niên feast is an occasion for family members, business partners and officials to gather, eat and exchange Tết wishes before the holiday. The rằm of the twelfth month may be when some families hold an early tất niên ceremony, but it is not the official tất niên day.
Why Is the Rằm of the Twelfth Month Important in Folk Belief?
The rằm of the twelfth month is important because it is the last full moon of the year, marking the end of a cycle of time. In folk belief, Vietnamese people hold that each month has two important days, the ngày sóc (first day) and the ngày vọng (full moon), when yin and yang harmonise and deities and ancestors can easily witness sincerity. The rằm of the twelfth month is the last vọng of the year, so the offerings are often given more attention.
Should One Make Offerings at the Rằm of the Twelfth Month?
Making offerings at the rằm of the twelfth month is a traditional practice of the Vietnamese, carrying the meaning of giving thanks and praying for peace. However, it is not a mandatory ceremony under the rules of any religion; it is a folk custom. Many families still keep up the rằm of the twelfth month as a way to remember the merits of ancestors and deities and to preserve cultural tradition. The offering can be simple or a full tray depending on the family's circumstances, as long as the heart is sincere.
