South Korea has officially transitioned to the international age counting standard, resulting in a nationwide age reduction. Starting Wednesday, official documents will reflect ages based on birthdates, aligning with global norms. Previously, South Koreans were considered one year old at birth, with everyone adding another year on New Year's Day. This unique system meant a baby born on December 31st would be two years old the next day.

While individuals can adjust their ages based on their birthdates, the shift presents cultural adjustments, particularly regarding social hierarchy. Respect for elders is deeply ingrained in Korean society, and age often dictates interactions. Schoolchildren traditionally inquire about each other's age before names. The change means some individuals will experience a two-year age reduction, leading to potentially awkward situations, like younger students now being the same age or even older than their former seniors. One teenager expressed frustration at having to wait months for his birthday to regain his previous age relative to his classmates.

This transition follows similar changes in other East Asian nations like China and Japan, which previously incorporated time in the womb into age calculations and observed New Year age advancements. They adopted Western standards in the 20th century. Despite the change, South Korea's mandatory military service will continue using the traditional age calculation method. Interestingly, the legal drinking age is now 19, down from 20, due to the new system.