Babies in Korea are considered to be 1 year old at birth

In many countries, a baby’s first birthday marks a joyous milestone for parents, honoring the many months of sleepless nights and hard work involved in welcoming a new family member. But in some places — like South Korea — babies are already considered 1 year old at birth. Korean culture calculates age in three different ways, and the oldest and most traditional way (often called “Korean age”) may have gotten its start by accounting for the time spent in utero, rounding up a nine-month gestation to a full year. 

Under this measurement, everyone gains another year of age on January 1, regardless of their actual birth date — meaning it’s possible for a baby born on December 31 to turn 2 years old the following day. Yet individual birthdays are still recorded and celebrated; in fact, South Korea has used the “international age” system that counts age by date of birth for medical and administrative purposes since 1962. A third age-counting method acts as a compromise between accuracy and culture: Babies are born at age 0, but gain a year on New Year’s Day. 

Knowing someone’s age is culturally important in Korea; it’s tied to language, impacting how people address their eldersand interact on social occasions. However, the traditional method of determining age does cause some confusion when it comes to administering medications, vaccinations, and health care procedures that are determined by one’s years, and has also caused issues with legal disputes. In December 2022, the South Korean government passed laws that standardized the use of international age, meaning many Koreans will technically become one to two years younger.

Happy New Year! You Are Now a Year Older in Korea

In the Korean peninsula, every person turns a year older on New Year’s.

THE NEW YEAR MIGHT BE the worst time to have a birthday. A birthday party in January struggles to attract attendees, you probably get combined holiday and birthday presents, and everyone else is too preoccupied thinking of all the resolutions they’re going to break to care about your big day.

Unless, that is, you’re from the Korean peninsula where everyone cares about your New Year birthday—because it is everyone’s birthday.

Koreans essentially have two separate celebrations for what the Western world would consider a birthday: their date of birth, and New Year’s, when everyone turns a year older. Interestingly enough, birthdays and age aren’t related to one another. Both of these celebrations are important, but they do not hold the same weight.

Individual birthdays are not as important as the New Year birthday. Some exceptions to this are the dol, or first birthday, and the 60th birthday

Eunjoo Shin, a South Korean citizen from Gunsan who resides in Seoul, says “I love my individual date of birth, but we consider New Year’s more important.” This importance is derived from the Korean emphasis on collectivity.

Collectively turning a year older gives Koreans a very particular concept of age. Once born, a baby is considered to be one year old, accounting for the time spent in the womb. The baby will turn two not a year after it is born, but on New Year’s. This means that Korean babies born on December 31st turn two on January 1st , even though they would be one day old in the rest of the world.

Traditional clothes, or hanboks, are worn during the Lunar New Year celebration. However, western clothing is becoming more and more common.

In the Korean peninsula, this difference is extremely important. Korean culture organizes hierarchical social relationships based on age. Juniors must treat seniors with respect, so knowing someone’s age is critical. Everyone born on the same year shares the same age, so they are equal. But a person born a day before the new year will be a year older than a person born a day after, and will thus be their senior.

What happens on a person’s date of birth? It is still an occasion to celebrate, it’s just not as big. Shin says that she usually has a small party with around five people, or goes out to eat with friends and family.

Tteokguk is eaten during the Lunar New Year. Traditionally, this soup was thought to be what made a person a year older. XIAOLO

Only certain birthdays, like the dol, or one-year birthday, and the 60th birthday, are considered of great importance. This is because for most of the peninsula’s history, many people died before these birthdays due to lack of medicine and markedly varying temperatures. If a baby survived after the first year, the chance of mortality decreased significantly, so it was an occasion for a great party. Likewise, it was not common for someone to live over 60, so it was seen as proper to revere elders who did.

Even the date of birth can be subject to variations. Most people today determine their birthday based on the solar calendar, as we do in the West. This birthday, yangryeok saeng-il, always falls on the same date. But some people, especially the older generations, still determine it based on the lunar calendar. This means that the date they celebrate their birthday, eumryeok saeng-il, changes every year.