All South Koreans will become younger next year

South Korea is to scrap its traditional method of counting ages and adopt the international standard – a change that that will knock one or two years off people’s ages on official documents but could take time to seep into daily life.
South Koreans are deemed to be a year old when they are born, and a year is added every 1 January. The unusual – and increasingly unpopular – custom means a baby born on New Year’s Eve becomes two years old as soon as the clock strikes midnight.
The complications do not end there: a separate system exists for calculating the age of men entering national service and the legal age to drink alcohol and smoke. In those cases, a person’s age is calculated from zero at birth and a year is added on New Year’s Day...
Jeong Da-eun, a 29-year-old office worker, said she welcomed the change, since she always had to think twice when asked her age when overseas. “I remember foreigners looking at me with puzzlement because it took me so long to come back with an answer,” she said.
The system’s origins are unclear. One theory is that turning one year old at birth takes into account time spent in the womb – with nine months rounded up to 12. Others link it to an ancient Asian numerical system that did not have the concept of zero.
More details at The Guardian.