In Korea, babies are considered one year old at birth, and they gain another year on New Year's Day, regardless of their actual birthday. This is known as the Korean age system, a tradition different from the international system.
The Korean age system adds a year to a person's age on New Year's Day, even if their birthday hasn't passed yet. So, a baby born on December 31st would be considered two years old on January 1st of the following year.
This age-counting system is a part of Korean cultural tradition, and it is used for social interactions, such as addressing others formally or informally. While the Korean age system is still prevalent, the government has recently adopted the international age system for official purposes.
