TL;DR: Hoàn giáp is when the stem-branch year returns to one's birth year after 60 years: someone born in the Đinh Mùi year 1967 meets the Đinh Mùi year again in 2027, after Tết on 6 February 2027. That year is 61 by Vietnamese reckoned age and the year of turning 60 by Western age; 60 by reckoned age is the Bính Ngọ year 2026. There is no single rule for the 60th celebration: the law starts longevity celebrations at 70 and old books record them at seventy or eighty, so each family chooses the year.
What is hoàn giáp?
Hoàn giáp is the point when the stem-branch year returns to a person's birth year, after one full 60-year cycle. The ten heavenly stems combine with the twelve earthly branches into 60 pairs, the sexagenary cycle; someone born in the Đinh Mùi year 1967 meets the Đinh Mùi year again in 2027.
This milestone follows the lunar year, not the solar year. The Đinh Mùi year 1967 ran from Tết on 9 February 1967 to 28 January 1968; the Đinh Mùi year 2027 begins at Tết on 6 February 2027. People born between 1 January and 8 February 1967 still belong to the Bính Ngọ year, so their hoàn giáp falls in Bính Ngọ 2026.
How do Vietnamese reckoned age and Western age differ at 60?
Vietnamese reckoned age (tuổi ta, or tuổi mụ) counts one year at birth and adds a year at every Tết; Western age counts completed years from the solar birthday. For someone born in the Đinh Mùi year (9 February 1967 to 28 January 1968):
- 60 by reckoned age: the Bính Ngọ year, from 17 February 2026 to 5 February 2027.
- 61 by reckoned age, also the hoàn giáp year: the Đinh Mùi year, from 6 February 2027.
- Turning 60 by Western age: on the solar birthday in 2027 (in January 2028 for those born in January 1968).
So reckoned age and the hoàn giáp year point to two different years: the hoàn giáp year coincides with turning 60 by Western age, not with 60 by reckoned age.
In which year should the 60th longevity celebration be held?
There is no single rule. In practice, some families celebrate in the year the person is 60 by reckoned age, some wait for the hoàn giáp year, and some hold it on the 60th birthday. For someone born in the Đinh Mùi year 1967, these fall in 2026 (60 by reckoned age) or 2027 (hoàn giáp, 60 by Western age).
The law does not set a milestone at 60 either. The 2009 Law on the Elderly tasks commune People's Committees, together with the local Elderly Association and the family, with organising longevity celebrations at ages 70, 75, 80, 85, 90, 95 and 100 or older[3]. A 60th celebration is therefore a private family matter.
At what age did Vietnamese traditionally celebrate longevity?
Phan Kế Bính's Việt Nam phong tục records that a well-off family with many children whose parents had reached seventy or eighty held a longevity ceremony for them, called lễ Thượng thọ[1]. On the day, the family first offered chicken and sticky rice, or the three sacrificial animals, or a pig or ox at the communal house, called bái tạ thần hưu, thanking the deities for granting the parents long life[1].
During the rite, each descendant offered a cup of longevity wine or a peach, called bàn đào chúc thọ, and then the village and guests were invited to celebrate[1]. Bùi Xuân Mỹ's Tục thờ cúng của người Việt records the same milestone of seventy or eighty[2]. By these two books, then, the traditional longevity milestone was seventy or eighty, not sixty.
What are the milestones for someone born in the Đinh Mùi year 1967?
| Milestone | Lunar year | Solar dates |
|---|---|---|
| Birth year | Đinh Mùi | 9 Feb 1967 to 28 Jan 1968 |
| 60 by reckoned age | Bính Ngọ | 17 Feb 2026 to 5 Feb 2027 |
| 61 by reckoned age, hoàn giáp | Đinh Mùi | 6 Feb 2027 to 25 Jan 2028 |
| Turning 60 by Western age | Đinh Mùi (mostly) | Birthday in 2027, or January 2028 |
| Celebration under the law | Not applicable | From age 70 |
The Tết dates in the table follow the Vietnamese lunar calendar.
Nhật Nguyệt's suggestion: how to choose the year?
If the family wants the literal sense of hoàn giáp, hold it in the Đinh Mùi year 2027, after Tết on 6 February 2027. If the family usually counts reckoned age, as for other rites, the year of 60 by reckoned age is Bính Ngọ 2026.
Before choosing, check the person's lunar birth date: someone born early in 1967 before Tết belongs to the Bính Ngọ year, and every milestone moves back one year.
