TL;DR: When a family member dies in a leap month, the tiểu tường rite (first anniversary) counts a full 12 months and the đại tường rite (end of mourning) counts a full 24 months from the date of death, so in a leap year these two rites must be adjusted to make up the full number of months. The annual death anniversary (húy nhật) after đại tường, however, is still offered on the exact day and in the main month of the death, not in the leap month. In many regions there is also the custom of the tiên thường offering on the afternoon of the day before and the chánh kỵ on the morning of the following day.
Why Is the Question "Which Month for the Giỗ When the Death Fell in a Leap Month?" So Complicated?
The Vietnamese lunar calendar is a lunisolar calendar, so every few years an intercalary month must be added to keep the calendar from drifting away from the solar terms. This creates years with two months of the same name, for example the year Quý Mão 2023 had a leap second month, the year Canh Tý 2020 had a leap fourth month, and the year Ất Tỵ 2025 had a leap sixth month. When a loved one passes away in that leap month, or when the giỗ falls in a leap year, families are often unsure which month to choose for the rite.
The short answer from the advisory board of Giác Ngộ newspaper is: only the two rites counted by the number of months since the death, tiểu tường (12 months) and đại tường (24 months), need adjustment when a leap year occurs; the annual giỗ afterwards is still held on the exact date and principal month of the death, not in the leap month[1][5].
How Are Tiểu Tường and Đại Tường Calculated?
According to Vietnamese folk custom, exactly 12 months after death is the tiểu tường rite, also called cúng giáp năm; exactly 24 months after death is the đại tường rite, also called cúng mãn tang[3]. These are two important milestones marking the completion of mourning by the descendants and the transition to regular ancestral worship.
Because they are counted by the number of months rather than a fixed date, these two rites must total a full 12 and 24 months, so in a year with a leap month the date of the rite has to be adjusted to match the full number of months. Giác Ngộ explains: "The time for cúng tiểu tường is counted 12 months (365 days) after death, and cúng đại tường is counted 24 months after death"[1].
A specific example given by Giác Ngộ: if a person died on the 3rd day of the second lunar month (the leap second month) in the year Quý Mão 2023, then tiểu tường is held on the 2nd day of the second lunar month in the year Giáp Thìn 2024, and đại tường on the 2nd day of the second lunar month in the year Ất Tỵ 2025. The date is moved back one day from the date of death so as to be exactly one year and two years, because holding it on the 3rd of the second month would exceed one and two years[1].
If the Death Fell in a Leap Month, Which Month Is the Annual Giỗ Held?
After the đại tường rite, the giỗ day (húy nhật) is counted on the exact date and principal month of the death, not by the leap month. Giác Ngộ writes: "After đại tường, the giỗ day (húy nhật) is counted on the 3rd of the second lunar month every year (because the leap month is the surplus month of a leap year, the giỗ day still chooses the principal month)"[1]. That means if in the future there is again a year with a leap second lunar month, the giỗ day remains the 3rd of the second lunar month of the first month, not the leap month.
This principle is also repeated in another case: "All giỗ rites during a year with a leap month are still carried out as normal, except tiểu tường (after 12 months) and đại tường (after 24 months), which need adjustment to make up the full number of months"[5]. Thus the leap month is only a "surplus month" and is not used as the marker for the annual giỗ.
What Should the Living Do If the Giỗ Falls in a Leap Month?
There are two common situations that confuse families, and both have clear solutions.
First case: the deceased died in the third lunar month, and in a leap year with two second lunar months the tiểu tường rite must be held in the (leap) second lunar month to be correct, because a full 12 months is counted. Giác Ngộ explains: "Although your father died in the third lunar month, the tiểu tường rite must be held in the (leap) second lunar month to be correct"[2]. The following year the đại tường rite also falls in the second lunar month, while the annual giỗ afterwards is still held in the third lunar month as normal[2].
Second case: the family has always held the giỗ for the deceased in the third lunar month, and this year has a leap second lunar month. Giác Ngộ answers: "This year (Quý Mão 2023), although it is a leap year with two second lunar months, you still hold the giỗ in the third lunar month as normal"[2].
Another example: the family holds the giỗ in the sixth lunar month, and this year has a leap sixth month. The answer is "hold the giỗ in the (first) sixth month. Because the (first) sixth month is the principal month and the leap month is the secondary month, the family's annual giỗ rites occurring in the sixth month are still carried out as usual, with no adjustment needed"[5].
However, there is one special case: if the person died in the seventh lunar month last year, and this year has a leap sixth lunar month, then the tiểu tường rite must be held in the leap sixth month, because only by the leap sixth month is a full 12 months reached[5]. This is the point that must be clearly distinguished between rites counted by month (tiểu tường, đại tường) and rites counted by day (the annual giỗ).
Comparison Table for Calculating Rite Dates in a Leap Year
| Type of rite | How it is counted | What to do in a leap year |
|---|---|---|
| Tiểu tường (giáp năm) | A full 12 months from the date of death | Adjust to make up 12 months (examples in the sources: it falls in the leap month, or the date is moved back one day) |
| Đại tường (mãn tang) | A full 24 months from the date of death | Adjust to make up 24 months (examples in the sources: moved back one month, or one day) |
| Annual giỗ (húy nhật) | The exact date and principal month of the death | Still held in the principal month, not the leap month |
| Giỗ falling in a leap month | Not counted by the leap month | Held in the principal month (the first month), no adjustment |
How Do the Sources Adjust Tiểu Tường and Đại Tường?
The general principle in these answers is to adjust so that the full number of months is complete, but the examples do not all adjust in the same way.
A person who died on the 3rd of the second lunar month (the leap second month) of 2023: tiểu tường on the 2nd of the second month of 2024, that is, one day earlier than the date of death[1]. A person who died on the 9th of the tenth lunar month of Mậu Tuất 2018: đại tường in Canh Tý 2020 (leap fourth month) on the 9th of the ninth month, that is, one month earlier than the date of death[3]. A person who died on the 20th of the eighth lunar month of Nhâm Dần 2022: in Quý Mão 2023 (leap second month) tiểu tường on the 20th of the seventh month, and in 2024 đại tường on the 20th of the seventh month[4]. A person who died in the third lunar month of 2022: tiểu tường in the leap second month of 2023[2]. A person who died in the seventh month of Giáp Thìn 2024: tiểu tường in the leap sixth month of 2025[5]. The sources give no single formula for every case, so this article adds no rule beyond these examples.
After đại tường, later giỗ are counted by day only, not by month, so whether or not the year is a leap year, the giỗ date stays the same[3].
Custom of Holding the Giỗ One Day Early and Over Two Days
Besides the calendar calculation, many regions also have the custom of holding the giỗ one day early. Giác Ngộ notes: "Many regions have the custom of holding the giỗ one day early (the 2nd of the second month). Some places hold the giỗ over two days, with the first day in the afternoon (tiên thường) and the main giỗ on the following morning (chánh kỵ)"[1].
This is a local custom, not a general rule. Some places hold it on one day, others over two days with different names for the afternoon and the morning. This shows that holding the giỗ is not only a matter of pure calendar calculation but is also tied to the customs of each region.
Can the Giỗ Be Flexibly Held on a Weekend?
Today, many families choose to hold the giỗ on the Saturday or Sunday closest to the giỗ day so that descendants living far away can gather. Giác Ngộ notes: "Today, some families flexibly hold the giỗ on a Saturday or Sunday (closest to the giỗ day) so that descendants from everywhere can attend fully"[1].
Spiritually, Giác Ngộ holds that the giỗ day "can be flexible according to circumstances, as long as everyone in the extended family (in the clan) is happy, remembers their roots, is grateful and follows the example of the deceased, and loves and understands one another more"[1].
What If the Giỗ Date Was Calculated Wrong?
Cases of calculating the giỗ date wrongly because a leap year was forgotten have also been advised by Giác Ngộ. When the mistake is discovered, the advisory board advises the family to prepare flowers and fruit, light incense and lamps at the altar of the deceased, dress properly, bow to the deceased, then kneel before the altar and pray, expressing remorse for the miscalculation and asking the deceased to understand and forgive[4].
After that, on the appointed day, the family holds the giỗ as normal with all sincerity. With relatives, they should sincerely admit the mistake and learn from it for the đại tường rite the following year[4]. Giác Ngộ emphasizes: "In Buddhism there is a saying 'When the heart is sincere, the Buddha bears witness', and in life too, the deceased will forgive the unintentional mistake of the descendants if they are sincerely repentant"[4].
Buddhist View on Holding the Giỗ
From the Buddhist point of view, holding the giỗ with reverence is a sincere remembrance of the deceased, expressing filial piety and gratitude to ancestors, and doing good deeds (if any) to dedicate the merit[1]. Giác Ngộ also explains further about karma and rebirth: within 49 days after death, praying, making offerings, and doing good deeds to dedicate merit to the deceased strongly support rebirth in a good realm; after 49 days, most have already been reborn, and then the giỗ rites serve only to remember the deceased[4].
Therefore, from this point of view, holding the giỗ on the wrong day does not greatly affect the suffering or happiness of the deceased; what matters is the filial heart of the living[4].
What Should Be Remembered in Short?
In a leap year, only two rites need adjustment: tiểu tường (a full 12 months) and đại tường (a full 24 months). The annual giỗ after đại tường is still held on the exact date and principal month of the death, not in the leap month. If the deceased died in a leap month, the annual giỗ still chooses the principal month, not the leap month. And even if there is a mistake in calculation, sincerity and filial piety remain the most important things from the Buddhist point of view.
