TL;DR: No evidence shows that picking a 'lucky' or auspicious wedding date makes a marriage last longer. In the Netherlands, couples who married on numerically special dates or Valentine's Day faced an 18 to 36 percent higher divorce risk, but most of that gap came from the couples' pre-existing traits rather than the wedding date itself. In Singapore, housing transactions dropped noticeably on days considered inauspicious by the lunar calendar, showing that beliefs about dates can shift real behavior.
Does choosing a wedding date make a marriage last longer?
The short answer is that no scientific evidence supports this. The largest study on the topic, by Jan Kabátek and David C. Ribar published in 2018 in the Journal of Population Economics, analyzed Dutch marriage and divorce registers and found that couples who married on dates considered special had an 18 to 36 percent higher divorce risk than couples who married on ordinary days. However, the authors themselves concluded that most of this gap came from the pre-existing traits of the couples who chose special dates, not from the wedding date itself.
In other words, choosing a date does not create risk. But choosing a special date correlates with a group of couples who differ in certain traits, and those traits are what actually predict the outcome.
What did the Kabátek and Ribar study do and find?
Kabátek and Ribar (2018) used administrative data from Dutch marriage and divorce registers, following couples over time to compare divorce risk between those who married on special dates and those who married on ordinary days.
The dates considered "special" in this study fell into two types: numerically special dates in the Western tradition (such as 07/07/2007, 08/08/2008, 09/09/2009, 10/10/2010, 11/11/2011, 12/12/2012) and Valentine's Day, February 14. These are dates many Western couples actively choose for the symbolic meaning of the numbers or the tie to the lovers' holiday.
The result: the special-date group had an 18 to 36 percent higher divorce risk than the ordinary-date group. But when the couples' pre-existing traits were controlled for (age, education, economic status, marital history, time together before marriage), most of the difference disappeared or shrank sharply.
This means couples who choose special dates are not a random sample of the population. They differ in many ways, and those differences explain most of the higher divorce risk. This is a classic selection effect in observational research.
Inauspicious lunar days in Singapore: belief shifts transaction schedules
Jia He and colleagues (2020), published in Management Science, studied Singapore's housing market and found that the number of home transactions dropped noticeably on days considered inauspicious by the lunar calendar.
This is evidence that beliefs about dates are not just a matter of private psychology but can be measured through market behavior. When a large enough group of buyers and sellers share the belief that a given day is bad for transactions, they shift to other days, and the total transactions on that day fall.
The mechanism is clear: belief changes behavior, behavior changes observable outcomes. This is not evidence that bad days cause anything; it is evidence that belief about bad days genuinely affects transaction schedules.
| Study | Data | Scope | Main finding |
|---|---|---|---|
| Kabátek and Ribar (2018) | Marriage and divorce registers | Netherlands | Weddings on special dates carry 18 to 36 percent higher divorce risk, mostly from couple traits |
| He et al. (2020) | Housing transactions | Singapore | Transaction volume falls on inauspicious lunar days |
| Helgertz and Scott (2020) | National register data | Sweden | Zodiac compatibility is unrelated to marriage or divorce |
Why can't we conclude that 'a good date ruins a marriage'?
This is the most important methodological point. When we see a higher divorce rate in the special-date group, we cannot conclude that the wedding date causes divorce. There are at least three reasons:
- First, this is an observational study, not a randomized experiment. No one randomly assigned people to a special-date group and an ordinary-date group. Couples chose their own dates, and that choice carries information about them.
- Second, couples who choose special dates may differ on many traits that cannot be fully measured, such as how much they value formality, their expectations about marriage, or social pressure. These traits could lead both to choosing a special date and to higher divorce risk.
- Third, as Kabátek and Ribar themselves concluded, when pre-existing traits are controlled for, most of the difference disappears. This shows the wedding date itself is not the cause.
In demographic and marriage-economics research, this phenomenon is called "selection into treatment": people are not randomly assigned to groups but choose for themselves, and that self-selection carries information about who they are. This is why observational marriage studies often use many control techniques to separate how much is selection and how much is a real effect.
What about zodiac and birth-year compatibility?
Jonas Helgertz and Kirk Scott (2020), published in the journal Genus, ran a longitudinal study on Swedish national register data, testing whether couples with astrologically compatible zodiac signs married and divorced differently from other couples. The result: no link was found between zodiac compatibility and either marriage or divorce.
This is one of the studies with the largest sample sizes and most reliable register data on the topic. Note that this result applies to Swedish data, with Western astrological sign classification. It does not mean every other system has been tested, but it is strong evidence that at least one popular system cannot predict marriage outcomes.
A clear distinction is needed: this study tested Western astrology (sun signs by date of birth). It did not test Eastern systems such as Bát Tự, Tam Hợp, or birth-year compatibility methods based on can chi. No study of comparable scale has tested Eastern systems on national register data.
What about Vietnam?
There is no research data on the link between wedding dates and marriage outcomes in Vietnam. Nor is there any study using the Vietnamese auspicious-day calendar to test whether date selection relates to divorce.
In practice, Vietnamese custom has a tradition of choosing an auspicious day and month for weddings. Phan Kế Bính's book Vietnamese Customs (1915) records that before a wedding, the groom's family had to "choose an auspicious day and month" to set the wedding date, and this was considered an indispensable step in the traditional wedding process. This is a description of custom, not evidence of the effectiveness of date selection.
Wedding season in Vietnam tends to cluster in months considered good, avoiding the seventh lunar month (the ghost month) and certain days. This creates a pattern similar to Singapore's: beliefs about dates shift action schedules. But no study in Vietnam has tested whether date selection relates to marriage outcomes.
What other factors predict a lasting marriage?
Demographic studies of marriage usually focus on measurable factors with predictive value, such as age at marriage, time together before the wedding, education, economic status, and relationship satisfaction. These are the factors controlled for in Kabátek and Ribar's study.
Notably, when these factors are controlled for, most of the divorce-risk gap between the special-date and ordinary-date groups disappears. This suggests that what happens before and during wedding preparation matters far more than the wedding date.
Nhật Nguyệt's suggestion
Nhật Nguyệt's suggestion: If you are preparing for a wedding and have chosen a date that puts your family at ease, there is no reason to worry about that date. No evidence shows a wedding date ruins or sustains a marriage. What is evidenced is what the two of you build before and after the wedding day.
Choosing a date that reassures the whole family is reasonable psychologically and culturally. It reduces anxiety, creates family consensus, and gives the couple a sense that everything has been prepared carefully. Those benefits are real, even if they do not come from the wedding date influencing the marriage's future.
What to avoid is letting date selection replace the two of you getting to know each other, agreeing on what matters, and preparing for shared life. No date is as good as the two of you truly understanding each other.
