Korea has a unique age counting system that can make foreigners a little confused. At the time of birth, a baby is already one year old since Koreans calculate the time babies spent in their mother’s womb as “one year.” On top of that, every Korean gets one year added to their age on New Year’s Day.
If a baby is born on New Year’s Eve, they will be two years old the following day. Another age system Korea has is the one determined by their birthday which is internationally recognized. However, starting in 2023, the internationally-used age determined by date of birth became the official system.